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Author Topic:   Mercury 125-HP Two-Stroke 2+2 Motor
boatdaze posted 01-11-2006 03:19 PM ET (US)   Profile for boatdaze   Send Email to boatdaze  
[Moderator's comment in March 2013: this thread was begun more than six years ago. This thread is closed for further new postings--jimh]

Hey guys--need your help here. Found a good deal on a 2003 125 HP Saltwater series Mercury, model 125EXLPT SW. What sort of performance should I expect on the 18' Outrage? Am I wasting my money and will be disappointed? Any thoughts are greatly apprectiated.
Thanks a bunch, Mark

Teak Oil posted 01-11-2006 03:32 PM ET (US)     Profile for Teak Oil  Send Email to Teak Oil     
Well if Tony's Outrage can almost hit 40 with a 115 4 stroke, you will probably be looking at 40-41 mph top end.

It will probably be adequate, if you are going from a 150 to the 125 four banger you will be dissapointed

Buckda posted 01-11-2006 03:38 PM ET (US)     Profile for Buckda  Send Email to Buckda     

Forum member Gep has a 130 HP Yamaha 2-stroke on his 18 and I cruised with him for more than 600 miles two summers ago. The boat performed very well and got great mileage.

Sure, I walked away from him in WOT runs, but how often are you running that fast?

Those Mercs run "strong" in the HP rating too - so you're definitely getting all 125 ponies out of a healthy engine. If it's a good deal, you don't need to be the fastest boat, and don't regularly run the boat fully loaded with people and gear, I'd pull the trigger.


boatdaze posted 01-11-2006 03:59 PM ET (US)     Profile for boatdaze  Send Email to boatdaze     
Thanks for the responses. I forgot to mention that it is a 25" shaft. Is that going to make a world of difference?
Buckda posted 01-11-2006 04:08 PM ET (US)     Profile for Buckda  Send Email to Buckda     
The classic 18' Outrage requires a 25 inch shaft.
prj posted 01-11-2006 04:45 PM ET (US)     Profile for prj  Send Email to prj     
I believe we've heard that the 125 HP Mercury is a strong runner.
I also recall it being a "2+2" design,
where 2 cylinders drop out at low RPMs.

Regarding that Yamaha 130 HP 4 cylinder engine,
I have one and think it's a particularly strong model,
evidenced by Plotman's results on his 22' Outrage
and my own on an 18' Outrage.

Dave, if you're walking away from Mike's 130,
he's just not leaning hard enough on the throttle!

sosmerc posted 01-11-2006 08:45 PM ET (US)     Profile for sosmerc  Send Email to sosmerc     
I'll be putting on my "flame suit" shortly after typing this......
I don't think you will like the 125 Merc. I like everything about these motors...EXCEPT THE WAY THEY RUN!!
They have been VERY troublesome for some. They are very touchy...some idle well, and others are very inconsistant.
They do not always accelerate cleanly...and around 1800-2200 RPM they can't make up their mind whether to run on 2, 3, or 4 cylinders. Once on plane and cruising, they are ok. Top end power is ok. When everything is PERFECT, they can even idle and troll OK. But RARELY is everything ok. I would not sell a 100, 115, or 125hp with the 2+4 system to anyone, except maybe my worst enemy! (on the positive side, they have brought me alot of work with all their problems).
LHG posted 01-11-2006 09:10 PM ET (US)     Profile for LHG    
Sos - that's interesting to hear you say that. I have never thought this 4 cylinder replacement for the in-line 6 was as good of an engine. I often wondered why Merc didn't re-design the in-line 6 for loop charging and oil injection instead. And now with the Verados, here we are back to an in-line 6 block!
jimh posted 01-11-2006 09:19 PM ET (US)     Profile for jimh  Send Email to jimh     
Unless the price is overwhelmingly attractive, I would avoid this motor.

The 2+2 design of this classic two-stroke makes its running characteristics somewhat famously poor. In short, the motor has all the attributes of a classic two-stroke:

The Good Characteristics
--good performance at wide open throttle
--survives in marine environment

And the Bad Characteristics
--rough idle
--rough running
--bad fuel economy
--hard starting
--high emissions

The fact that this approach to design (using cylinders which cut in and out depending on engine speed) has never been used in another Mercury motor ought to tell you all you need about this engine.

Also, it is a fairly large displacement four-cylinder engine without any balancing shafts. It will have inherent vibration problems. Most four cylinder engines of this displacement built currently have elaborate dual balancing shafts to smooth out the engine vibration. (Cf. the new Suzuki and Yamaha four cylinder engines.)

Very few in-line four cylinder outboard have been built. This alone says something about them.

LHG posted 01-11-2006 10:08 PM ET (US)     Profile for LHG    
But with the new-4-strokes, Jim, all of that seems to be changing. Everybody is now making them, and they seem to have solved the crank balancing situation and are excellent engines. From 75 up to 175HP, L4's are now the name of the game with all brands except Evinrude, who I don't think has EVER made one.

Why have smaller V-4's and V-6's been avoided? I think it's the weight of a dual overhead cam valve train. The in-lines excel here.

jimh posted 01-11-2006 10:29 PM ET (US)     Profile for jimh  Send Email to jimh     
All the 4-cylinder engines made today have balancing shafts except the Mercury Verado 4. The Verado 4 is a very small displacement engine so its designers would offer the notion that you can get away with no balancing shafts in really small displacement engines. They just chopped off two cylders of their 6-cylinder engine. The six in-line engine is beautifully balanced, but the 4-cylinder version is not.

The larger displacement engines have balancing shafts to correct the vibration problem inherent in the four-cylinder in-line design. See the Yamaha, Suzuki, and Honda catalogues for details about their balance shaft 4-cylinder engines.

Also, with a four-stroke, going to a V-block doubles the costs because you have to duplicate all of those expensive, heavy, mechanically complicated cam shafts, bearings, valves, drive gears, chain drives, chain tensioners, etc. That is why the four-stroke engines cannot afford to make a V-4 block. It would be hideously complicated, expensive, and heavy. And with the balance shafts there is even more complexity to them. More chains or gears to drive the balance shafts, more bearings, more weight. I don't think anyone has ever made a V-4 four-stroke, have they? Going to a v-block would double the cost.

Since Evinrude two-strokes do not worry about having 200 to 400 additional components to add two or four cam shafts to their V-blocks, they go with the v-block design. A two-stroke cylinder head only has two parts, so no big deal to go to a v-block and have two cylinder heads instead of one.

The old Mercury 125-HP 2+2 has no balance shafts, large displacement, and plenty of vibration. That is why they limit the red line to a very curiously low 5,250-RPM. And they do mean red line at that speed.

sosmerc posted 01-12-2006 11:34 AM ET (US)     Profile for sosmerc  Send Email to sosmerc     
Merc has had some smooth running inline 4 cylinder 2 strokes in the past. There was a 65hp 2 stroke called the 650 that was an EXCELLENT motor. Even the 80 and 85hp versions were pretty smooth runners. So Merc knew how to do it years ago. The L4 100, 115 and 125 just didn't work out right.
I've always felt that Merc could have taken the older inline six and brought it up to date with fuel injection and lost foam casting, oil injection, etc. and it would have been a hugh winner. But, the old "tower of power" has now been relegated to ancient history. Let's hope the new "tower of power" turns out to be worthy of the title.
It certainly has alot to work with!!
jimh posted 01-13-2006 12:40 AM ET (US)     Profile for jimh  Send Email to jimh     
I used to have a 1976 50-HP Mercury four cylinder in-line engine. It ran rather smoothly, but, of course, the displacement was a tiny 11-cubic-inches per cylinder. I don't think there was enough mass in motion in that drive train to vibrate very much--again, very small displacement engine, 44-cubic-inches total or about 721-cc.

I don't understand all the physics involved, but for some reason three cylinder two-stroke in-line engines are real runners, smoother than four cylinders.

LHG posted 01-13-2006 01:20 AM ET (US)     Profile for LHG    
I don't know Jim. I used to have one of those little 4 cylinder Merc 50's too, a 1970 model on my 1958 13 Sport, and it had the reputation of being the smoothest engines of it's time. One of Mercury's great 2-strokes. Compared to this engine, those terrible two cylinder OMC 40's of the day, which didn't even have CD ignition, were really rough, powerless and obsolete, with old fashioned props, no power trim, no single handle control, etc..
skookum point posted 01-13-2006 11:52 AM ET (US)     Profile for skookum point  Send Email to skookum point     
I recently got rid of the Merc 125 2+2 that I had on my Montauk because of its lack of mid-rpm performance. It ran fast and strong in the upper rpm range and was ok at under 1700 rpm, but there is no middle, it's like the throttle is an off-on switch. If you want to be able to cruise on a slow plane this is not the motor you want. It was impossible to run the Montauk at any speed between 7 and 25 mph. However at WOT it ran 49 mph and still could have turned a prop with more pitch. There is an unavoidable whiplash when all cylinders suddenly kick in at around 1800 - 2000 rpm and that lack of a smooth transition during acceleration was a constant source of irritation. I recently replaced the 125 with a Merc 90 2-stroke and it has much better "driveability" with a smooth transition and the ability to cruise in the 15 to 25mph range.

I cannot recommend the 125 on a Montauk although on your heavier boat the problems I have mentioned might be less apparent.

boatdaze posted 01-17-2006 12:30 PM ET (US)     Profile for boatdaze  Send Email to boatdaze     
Thanks to everyone who responded, if it was not for this site, I would have bought the engine. Now I know why he had it for so long and it was so cheap.
I ended up buying a new 150 Yamaha EFI instead. [Changed the topic to an entirely new focus. The discussions that resulted have been deleted from this thread.--moderator]
Thanks again to all.
Plotman posted 01-17-2006 06:24 PM ET (US)     Profile for Plotman  Send Email to Plotman     
I have a friend who has this engine on his walleye boat. He "turned off" the cutout feature by replacing some carb parts - I know this engine has no idle ports on 2 cyliders, and I think the carb is diffeent too - anyway, he spent a little bit on parts, and now loves the engine.
John W posted 01-17-2006 09:42 PM ET (US)     Profile for John W  Send Email to John W     
The decision has been made, and I'm sure the original poster will be very happy with a new 150 hp Yamaha. But I think the 125 hp Merc is getting unfairlty abused here. My father owns one and the idle is fine...not a four stroke in smoothness, but typical of a carb two stroke (it idles better than my Johnson v6 150). I was surprised how well it ran at slow speeds given that only two cylinders were firing. These motors do have a rough spot in the mid-range, where it crosses into running on all four cylinders, but at slow speeds and at planing speeds this motor runs well.

A friend of mine who guided for years put over 4000 hours on his 2+2 Merc 115, which is based on the same block, until the motor gave out after overheating due to a water passage blockage. His only complaint about that motor was that it was difficult to start...but my father's 125 starts fine.

This would not be my first choice in a new motor, but if a great deal was available I would not shy away from this model.

My 2 cents.

creg posted 01-03-2010 03:02 PM ET (US)     Profile for creg  Send Email to creg     
I really like my [2002 Mercury two-cycle 2+2] 115-HP outboard engine, and I have not experienced idle problems. The transition from two cylinders to four cylinder is no big deal for me. I am old school, like when the secondaries on my four barrel kicked in on my 327 Chevelle. My [engine] speeds are idle or beyond 2,000-RPM. Bass fishing, blast off, hole to hole, back to weigh-in site, pretty easy. My motor is on a TRACKER v18 tournament. The top speed is 50-MPH at 5,200-RPM with 21-inch pitch propeller. [Say he is] thinking about re-jetting main carburetor jets to 125-size. [Inquires if] anybody knows anything about this. [Says he has] read some stuff on-line but really pretty vague. One [unidentified] guy [somewhere] said the difference between a 115-HP and a 125-HP classic was the number of cylinders.
Russ 13 posted 01-04-2010 10:49 PM ET (US)     Profile for Russ 13  Send Email to Russ 13     
I owned a 1990 Mercury 2 + 2 that ran good, but the only quirk was the jump from 2 to 4 cylinders at 1,800 RPM--tough on skiers. I re-jetted mine down in size for high altitude running. At the time, I was running the boat at 5,000-foot elevation. This brought the carburetors back to the correct mix. If you are running LESS than 3,000-feet above sea level, I would NOT re-jet the engine. Running the TCW-3 top Mercury or Yama-lube oil will reduce smoke and protect the engine. I would stay away from the bargain or generic oils. Currently a VERY happy Yamaha owner.
jimh posted 01-04-2010 11:09 PM ET (US)     Profile for jimh  Send Email to jimh     
My experience is that people who have a particular motor often tend to become fond of it. Even a motor like the classic Mercury 2+2 which was notorious for its very rough jump between two cylinders and four cylinders, which was an extraordinarily simple and unsophisticated two-cycle motor with carburetors, lacking in any sort of noise reduction, smoothness, or refinement, an in-line large-displacement four-cylinder motor with no balancing shafts that had lots of vibration--even this motor could attract some supporters, particularly those already predisposed to love everything Mercury. But viewed in the light of the dawn of a new decade, in 2010, these are really old-fashioned, rough-running, high-emission, smoke-belching, nasty old two-cycle motors from another era. Throw in the kludge gear case and lower unit they're connected to, and you've got quite an engineering disaster. They were designed in the 1970's with technology from the 1960's, built cheaply to make a profit until the 1990's, and finally removed from the market, not by choice, but from a realization that no one would ever actually buy one of these things anymore, now that there were so many far better outboard motors available in that horsepower range.
Tohsgib posted 01-05-2010 10:18 AM ET (US)     Profile for Tohsgib  Send Email to Tohsgib     
Bravo Jim....Bravo!
jimh posted 01-05-2010 09:42 PM ET (US)     Profile for jimh  Send Email to jimh     
Thank you, Nick. If we are going to get nostalgic, we ought to at least get nostalgic about a motor that was at least an above-average motor for its time. No point in getting nostalgic for a motor that was very marginal when it was new, and hopelessly out of date now.
brisboats posted 01-06-2010 01:08 PM ET (US)     Profile for brisboats  Send Email to brisboats     
I have never owned a Mercury 2+2 motor and probably wouldn't seek one out but Jim's comment about nostalgia struck me. "No point in getting nostalgic for a motor that was very marginal when it was new, and hopelessly out of date now". Truth is, people often get more nostalgic about things that have had terrible track records as engineering marvels. Perfect example would be an Edsel. Once a miserable failure enough folks have gotten nostalgic about them to drive prices over $200,000 for a coveted model. One of my favorite cars is the original VW bug. I have owned numerous examples yet it is at its base a slow, unsafe car with marginal brakes prone to rust and not all that efficient by today's standards. Yet even after driving and owning some much better engineered cars I always come back to giving the lowly bug a spot in my garage. I grew up with the bug and get a bit nostalgic every time I see one. The memories of freezing New York Winters in a car with lackluster heat, hard to start and windows that would not defrost have faded to fond memories of the wonderful woolen smell of the backseat. And at five or six years old sitting with my sister on the roof top of our family's 65 with out legs hanging in the sunroof watching July fireworks.

The best old outboard is the one that consistently brings you back to the dock. Easy to get a warm fuzzy nostalgic feeling for one that has done that several hundred or thousand of times no matter what brand is emblazoned on the cowl.


Clark Roberts posted 01-07-2010 07:45 AM ET (US)     Profile for Clark Roberts  Send Email to Clark Roberts     
I wonder if jimh or Tohsgib would accept a tow from a Mercury 2+2? Just saying... Clark... Spruce Creek Navy
jimh posted 01-07-2010 09:43 AM ET (US)     Profile for jimh  Send Email to jimh     
I would be interested to see a commercial tow boat operator who was using a Mercury 2+2 115-HP or 125-HP engine. That would be a strong endorsement of the engine as a very reliable engine with the sort of excellent control over engine speed and power needed in a commercial towing operation.

Most of the applications of this engine I have seen were on boats which when new were sold at a low price point as a starter-boat or low-end boat deal.

It is curious that this same general configuration of bore and stroke for the cylinders, when reduced to a three cylinder engine as used in a 90-HP model, and relieved of the odd displacement on demand configuration of the 2+2, became a much better engine: the classic Mercury three-cylinder 90-HP. Many owners of the Mercury three-cylinder 90-HP engine sing their praise.

jimh posted 01-08-2010 11:26 AM ET (US)     Profile for jimh  Send Email to jimh     
Re the Edsel and the price a used one can fetch nowadays:

The reason for the Edsel's failure was the poor quality of manufacturing it. The Edsel was not built on its own assembly line. It was built on a shared assembly line. About 98-percent of the cars on the line were another model. The legend goes that the manufacturing facility did not want to reduce their production rate of the other brand, so they increased the speed of the assembly line by a few percent to compensate for the extra output of the Edsel cars. There was nothing particularly flawed about the design.

The limited number of cars produced has resulted in a very limited number of Edsel cars surviving. This scarcity accounts for the higher price of them as collectable cars.

Re the Mercury 2+2 engines:

Of all the comments offered in this discussion, I give the greatest weight to those from sosmerc, who is in the business of repairing and servicing Mercury engines. He says:

"I would not sell a 100, 115, or 125-HP with the 2+[2] system to anyone, except maybe my worst enemy!"

brisboats posted 01-08-2010 02:05 PM ET (US)     Profile for brisboats  Send Email to brisboats     
As for the failure of Edsel, even the experts and avid enthusiast for the car cannot cite a sole reason for its failure. Most will agree it was the wrong car at the wrong time and way overpriced. Undeniable though the name Edsel did become synonymous with failure. The market evaporated, most got crushed and Ford lost millions. "We could have another Edsel on our hands" rang through boardrooms whenever a debacle was expected for decades.

As for the 2+2 Mercury it may well be the worst outboard ever made. But people will get nostalgic about the darndest things.

When the new technology begins to wear out and fail I can see many getting nostalgic for any healthy example remaining of the simple, rough running, smoke belching, high emission, nasty two stroke motors from a bygone era.


Jorgen posted 01-08-2010 02:38 PM ET (US)     Profile for Jorgen  Send Email to Jorgen     
Dont buy it, my advice.

I had one on a 17 Dauntless we had, had a lot of problems, powerpack faillure, stator pack problem, head gasket leaking.

Spent lot of time on a sh***y motor. Overall, these are not the best Mercury made.

L H G posted 01-10-2010 06:26 PM ET (US)     Profile for L H G    
I fail to see the reason, and archived content value to ContinuousWave, for running down this (introduced in 1989) Mercury outboard product. Many participants here own Post Classic Boston Whalers which came with these engines. Where is the pleasure and value of trashing this American made product for the second time around (first in 2006 and now in 2010)?

DeeVee posted 01-10-2010 11:02 PM ET (US)     Profile for DeeVee  Send Email to DeeVee     
For what it's worth:

My brother-in-law had a 1986 Montauk that he repowered with one of the 2+2 115 Mercury engines. It was a little quirky, but once we got used to it we loved it. It was a screamer on the Montauk. It looked pretty badass too:)

Doug Vazquez

jimh posted 01-10-2010 11:11 PM ET (US)     Profile for jimh  Send Email to jimh     
As the voice-over introduction used to say to the television series NAKED CITY:

There are half a million stories in the archives of CONTINUOUSWAVE.

This has been one of them.

adlert posted 01-11-2010 07:50 AM ET (US)     Profile for adlert  Send Email to adlert     
Interestingly, all of the fasteners on these "2+2" engines are metric--not typical of American-made Mercury engines of the time. I'm not certain, but I believe that the these powerheads were actually designed and made in Japan. I was told once (can't remember the source), that they were supplied by Yamaha. Wouldn't be too suprising given the established working relationship at that time.
jimh posted 01-12-2010 08:56 AM ET (US)     Profile for jimh  Send Email to jimh     
There is a general theme used by many Mercury brand enthusiasts regarding the relationship of Mercury to Yamaha that tends to ascribe any problem that occurs in a Mercury outboard engine to its origin as a Yamaha product. This same approach was used to explain the awful problems with carburetor fouling that occurred with certain Mercury 90-HP FOURSTROKE motors which used powerheads made by Yamaha. However, in regard to this Mercury 2+2 engine, I have never heard it proposed that the Mercury 2+2 engine was really a Yamaha product. I don't know of any corresponding Yamaha engine that used this powerhead.

There was a time in the United States when there was quite a trend toward use of Metric fasteners. Indeed, the automobile manufacturers switched to Metric fasteners almost exclusively many years ago. The use of Metric fasteners does not provide conclusive proof that a product is of foreign origin.

adlert posted 01-12-2010 03:58 PM ET (US)     Profile for adlert  Send Email to adlert     
I agree Jim regarding the use of metric fasteners. I do not however know of any other USA Mercury products that used metric fasteners during this engine's time frame at least. And it wasn't just some of the fasteners as is often (annoyingly) is seen on some American products; all of the powerhead fasteners were metric if I remember correctly. This engine was also sold under the Mariner name not that that means much.

As an aside, I did not mean to ascribe any perceived shortcomings to Yamaha. I actually found these engines to be quite reliable and their owners (my customers) seemed generally quite happy. Running properly, these engines idle smoother than most inline 4's due to the slight load that they operate under (I assume).

I'm curious so I'll see if I can come up with more definitive information regarding this engine's origin. I would appreciate it if anyone owning one of these could take a quick look at their model engine ID plate or their powerhead for a possible easy resolution. My early 80's Mariner 25 hp engines say "made in Japan" right on the tag.

Tom W Clark posted 01-12-2010 04:12 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
The Mercury four cylinder 2+2 outboards are all Mercury.

The Mariner brand started in the late 1970s. Those early Mariner motors were Yamahas imported by Mercury and sold with different decals. That is how Yamaha got their foot in the door of the American outboard market.

adlert posted 01-13-2010 08:51 AM ET (US)     Profile for adlert  Send Email to adlert     
I suppose I'm off topic, on a very old thread, and now beating a dead horse but Tom, how do you know this statement you made to be true?

"The Mercury four cylinder 2+2 outboards are all Mercury."

I'm just curious. It still seems very odd to me that the good folks at Mercury would choose to use metric fasteners for this one engine model and not any of the others they were building during that period (to my knowledge). Maybe this powerhead was designed and built by Mercury, but assembled out of the country? I'm going to try to track down the roaming Mercury representative that used to check on us back in the day and see if he knows anything. I vaguely remember him being the one who mentioned it, though I still wouldn't take that as being conclusive.

I'm quite familiar with the Yamaha/Mercury relationship in the late 70's - 80's. These old, smaller Mariners (Yamahas) are great deals as used engines around here. In the past 6 months I've purchased two 25 hp's and a 20 hp all in fine shape and for under $600 total. Wonderful machines weighing in at around 103 lbs each.

sosmerc posted 01-14-2010 05:33 PM ET (US)     Profile for sosmerc  Send Email to sosmerc     
The 1980 and 1981 Mercury 18hp and 25hp engines had metric fasteners, but the engines were made here in the USA. They also came with chrome bores with no sleeves. I guess they were sort of "ahead of their time" :)
creg posted 01-18-2010 05:25 PM ET (US)     Profile for creg  Send Email to creg     
Sometimes people speak with alot of authority without adequate information. Mercury 2 + 2 engines do not have head gaskets or power packs, they have a cover plate over domed cylinders and I assume the power packs referred to are coils. Mercury 2 + 2 were manufactured into at least 2004. Technology, fuel injection, advanced ignitions, IAT sensors are kool and work well, however when it quits dont even open the cowling. You wont have the specs or special tools required to make a repair to get back to shore, use your cell phone to call for help and deliver your new and improved outboard back to your dealer for repair. oh! and after you call for help, call your credit card company to check your limit. Ive had a variety of carbureted outboards since a kid with a twelve foot jon. I have never been back to a dealer for repair, there might be something to be said about simplicity.
jimh posted 01-18-2010 06:13 PM ET (US)     Profile for jimh  Send Email to jimh     
The term "power pack" is mainly an OMC term. Mercury calls this component a "switch box." GOOGLE "switch box" and see how often this component comes up in Mercury ignition repairs--quite often.

The Luddite anti-technology argument is not convincing. These days you can get a billion transistors for about $50. It makes absolutely no sense to not use a few transistors in a product. They are the cheapest components available. There is a general theorem that in the current era of transistors whose cost is so low they're practically free, any product that fails to utilize a lot of transistors is doomed. The Mercury 2+2 is an excellent example of the theorem having been proven to be true.

Even if offered a limited choice of similar two-cycle engines from the same era, I can't imagine anyone would prefer the Mercury 2+2 over a OMC V4 or a Yamaha V4. This engine was not a success in its own era, and no amount of wishful nostalgia can turn it into anything better than it was at its best: a third place finisher in the 115-HP to 125-HP four-cylinder engine market of the late 1980's.

creg posted 01-18-2010 06:36 PM ET (US)     Profile for creg  Send Email to creg     
[I] have always heard the only difference in very closely power rated outboards "is the carb jets." WRONG. I switched out carburetor jets on my Merc 2+2 115hp to 125hp sizes--it runs like _____. I am getting ready to change back to original jets unless someone can help pretty quick It seemed like something to try while there was a foot of snow outside. Russ 13--should have taken your advice. Thanks for any advice or real difference in these engines.
creg posted 01-18-2010 06:51 PM ET (US)     Profile for creg  Send Email to creg     
Transistors maybe virtually free until they are encapsulated into a module with a part number and then [they're] worth hundreds of dollars. I was employed by GE. Take some simple electronic components, pour green [epoxy] over them, and [voila]--call it ge3412976a and [it is] worth a fortune as a replacement part. And to not pretend to know everything, what is Luddit? Did someone miss the point about being repairable on the water? This could be truly a life saver.
creg posted 01-18-2010 07:06 PM ET (US)     Profile for creg  Send Email to creg     
In the [Mercury] manual [the power pack or switch boxes] are referred to as a capacitor discharge module (CDM), one per cylinder. The CDM integrades the capacitor discharge module ( or switch box) and ignition coil into one unit.
L H G posted 01-18-2010 07:20 PM ET (US)     Profile for L H G    
The bucket cowling Mercury 2+2 engines were manufactured 1995-2005. I see a lot of them. Many Post-Classic Whalers came with them.

But speaking of [changed topic to a completely different motor, then posted links to pictures of his boat.]

Jorgen posted 01-18-2010 08:26 PM ET (US)     Profile for Jorgen  Send Email to Jorgen     
[Bit on the change of topic. Sorry, not going to let this discussion of the Mercury 2+2 motor get turned into a love fest on another topic--jimh]
jimh posted 01-18-2010 09:15 PM ET (US)     Profile for jimh  Send Email to jimh     
The term Luddite is in the dictionary.

The discussion here is not whether Mercury ever made a decent motor. I am willing to stipulate to that. We are discussing the Mercury 2+2 motor. Actually, I cannot recall ever seeing one of these motors on the water and in running condition. This of course rules out seeing one of them on a Boston Whaler. I cannot even recall ever seeing a Boston Whaler catalogue showing a Boston Whaler boat with one of these motors. It would be like, to quote a favorite expression of an old friend of mine, the inverse of "putting lipstick on a pig."

Really, stop trying to glorify this motor. It was an aberration. There is a good reason they don't make them any more. There is a good reason they never used this 2+2 technique again. There is a good reason they don't make motors with carburetors that don't have idle jets.

The argument that manufacturers place a big mark-up on parts for which they are the sole source is not convincing. This is called screwing your customers. Actually, I will give Mercury a big nod in that regard.

creg posted 01-18-2010 10:39 PM ET (US)     Profile for creg  Send Email to creg     
If someone hasn't seen a [Mercury] 2+2 in operation, either they [don't] get on the water often enough or they live on the moon where there is no water. There are thousands out there. [Don't] even try to imply [Mercury] is the only manufacturer with outrageous renewal part prices. My fishing partner [changed topic to talk about a different motor.]
jimh posted 01-18-2010 11:21 PM ET (US)     Profile for jimh  Send Email to jimh     
Creg--Please don't turn this discussion of the Mercury 2+2 motor into a discussion of who is qualified to give opinions on this motor. I already mentioned the most influential opinion given--the comments of a devout Mercury fan and a Mercury service technician. He said--don't cringe too much bit I am going to reprint his comment again--"I would not sell a 100, 115, or 125hp with the 2+[2] system to anyone, except maybe my worst enemy!"

Are you now going to assert that this well-know Mercury technician, and admitted general fan of all Mercury motors, is also not qualified to give opinions on the motor? We could easily ask--who are you? We don't even know who you are. Now you're telling us who is qualified to comment on a motor? Don't take this path, you are standing into danger.

When people say they "see a lot of these motor," do they really mean that? What is "a lot?" One or two every couple of years? Honestly, I cannot think of any of these motors that I have seen running. A good friend of mine has one, but it is always out of service with something broken down. He says when it did run, it ran like a bandit at wide-open throttle until something broke.

Tom W Clark posted 01-19-2010 12:16 AM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
I cannot even recall ever seeing a Boston Whaler catalogue showing a Boston Whaler boat with one of these motors.

The 1991, 1992, 1993 and 1994 recreational and Commercial Products catalogs all show examples of such motors on Whalers.

creg posted 01-19-2010 12:26 AM ET (US)     Profile for creg  Send Email to creg     
If you take time to look back I stated I like my 2+2 and requested info about carb jetting. I'm speaking from first hand experience, I own one and use it at least 50 to 80 times annually and do any and all maintenance. Im not getting any technical info as requested just the 2+2 is a lousy outboard and on and on about some merc tech. Quite frankly Im tired of the constant bashing without any useful information. I'm done.
jimh posted 01-19-2010 01:10 AM ET (US)     Profile for jimh  Send Email to jimh     
You should start a new discussion if you wish to change the topic to seek advice about making a repair or modification to your motor. This discussion had been dormant for several years. Its topic was the general performance of the 2+2 Mercury motor. If you want to get advice on making repairs or modifications, use the REPAIRS/MODS discussion. Post a new article. Make your inquiry clear.
L H G posted 01-19-2010 01:34 AM ET (US)     Profile for L H G    
Jim - with regard to your post:

"We are discussing the Mercury 2+2 motor. Actually, I cannot recall ever seeing one of these motors on the water and in running condition. This of course rules out seeing one of them on a Boston Whaler. I cannot even recall ever seeing a Boston Whaler catalogue showing a Boston Whaler boat with one of these motors. It would be like, to quote a favorite expression of an old friend of mine, the inverse of "putting lipstick on a pig."

I am afraid your memory is indeed failing you.

Please see Cetacea Page 71. You have posted some good photos of a "2 + 2" on a Whaler Nantucket. Also, please see your photo of a Nantucket equipped with one of these on Cetacea page 78, 2nd photo. I saw this engine underway, which means you probably did too, and was surprised to see how well it pushed the Nantucket (Outrage 190). A very strong and powerful engine.

You are in over your head on this one! Why not give the Nantucket/190 Outrage owners on this site a break?

jimh posted 01-19-2010 02:05 AM ET (US)     Profile for jimh  Send Email to jimh     
Larry--I often swim in water over my head. I am able to keep afloat. Even without a PFD.

If you review my comments, I have been effusive in my praise of the good qualities of this motor. I have said it was:

--good performance at wide open throttle
--survives in marine environment
--runs like a bandit at full throttle

These are my exact words, and you seem to be in agreement with me in this as you have mentioned how well you recall a 2+2 motor could move a particular boat. I don't recall the particular boat. It escapes my memory.

However, I am a realist. I also pointed out the problems with this particular Mercury 2+2 motor's design:

--four-cylinder inline with large displacement and no balancing shafts
--awkward transition between two-cyclinder and four-cylinder operation

In this regard I have a lot of buoyancy. The problems with in-line four cylinder engines and vibration are very well known. It is only with more modern engines and the more demanding customers of the modern day that the vibration problems of in-line four-cylinder engines without balance shafts have become more prominent. With regard to the transition in cylinder activation, this is a characteristic that is overwhelmingly mentioned as unusual about this motor, and most comments are negative.

I also cited these characteristics the Mercury 2+2 shares will all older two-cycle engines:

--high emission
--bad fuel economy
--rough starting
--rough running until warmed up

This is nothing but the truth.

In regard to a prospective buyer purchasing a motor of this type, my advice was quite clear: the price would be very important, and a strong price incentive could overcome the known drawbacks.

Let's not be Pollyannish about this Mercury. The way some people have been praising it, you'd have to wonder why Mercury would have bothered to develop the Verado four-cycle engine to replace this thing.

jimh posted 01-19-2010 02:23 AM ET (US)     Profile for jimh  Send Email to jimh     
Larry--The pictures you mention in Cetacea all show Boston Whaler boats owned by dealers sitting on trailers and offered for sale at a time when Boston Whaler was owned by Brunswick and only sold Mercury motors. I said I could not recall seeing one of these motors on a boat on the water and underway. The existence of those pictures is not in conflict with what I said. It is not particularly surprising that a Boston Whaler boat in c.2004 would have a Mercury motor. There was a mandatory tie-in sale of a Mercury motor with a Boston Whaler boat at that time.

As for the pictures in catalogues, I did get a laugh from Tom's post about the early 1990's catalogues. My collection does not go back that far, so I am not surprised at my failure to recall seeing those pictures.

Tom W Clark posted 01-19-2010 11:57 AM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
As for the pictures in catalogues, I did get a laugh from Tom's post about the early 1990's catalogues. My collection does not go back that far, so I am not surprised at my failure to recall seeing those pictures.

Jim -- You wound me!

Having provided you with no less than two sets of the Boston Whaler Catalog Collection, 1958-2006, I would have expected you to have the index.htm file saved in your browser's Bookmarks menu, as I and hundreds of others hardcore Whaler enthusiasts have done so close examination of factory literature can be made in mere seconds.

But apparently, you do not make use of this excellent resource ;-)

jimh posted 01-19-2010 12:04 PM ET (US)     Profile for jimh  Send Email to jimh     
Tom--I have a shortcut to the catalogue collection files on my desktop, and I use it all the time to look up all sorts of things, but I have not spent too much time browsing the catalogues the way you would with a real printed catalogue--you know what I mean, idly turning the pages and dreamily looking at all the beautiful boats and motors.

I can't say that I have looked at every catalogue and every page. If there is a 125-HP Mercury two-cycle among the motors shown, your testimony goes without question.

I am perfectly comfortable with what the Mercury 2+2 motor is, but I am resistant to make it something it was not, even in the wistful remembrance of things past.

calmc posted 01-19-2010 04:54 PM ET (US)     Profile for calmc    
[Completely off topic article deleted.]
L H G posted 01-20-2010 02:43 PM ET (US)     Profile for L H G    
I still fail to see why certain people here have trashed this engine. In re-reading the thread, only one person, someone mostly unknown from Europe, has had mechanical problems with one, and with no real explanation as to why he hated it and details of the problems. The absence of other "breakdown posts" over the last 10 years indicates to me it's one very highly reliable engine.

Two others have mentioned not liking the strong power application at 1800 RPM, but reported no mechanical problems. So be it. Most of the beating this engine is taking is from people who have never owned one. So no credibility there.

There have been many more instances here of failures, warranty and mechanical problems with the E-tec 90's (from their owners) than there have been with the 2 + 2's. Many Nantucket owners here use these engines with no mechanical or performance problems indicated.

Also, I have never seen another boating website where the Moderator himself jumps on a particular engine and repeatedly dumps on it. Generally Site Moderators don't do that sort of thing, and avoid that sort of bias. Jimh is the most frequent contibutor to this thread, having posted at least 14 times to damage the reputation (and to decrease the value of those owned by people here) of this engine, which indirectly, subtly, damages the reputation of Mercury too, making it harder for Boston Whaler to sell boats. Why?

I don't own one of these engines, and have no experiece with them, and hence can't comment on their performance or reliability. But I have seen a LOT of them on the water, and they all seem to run well.

But it does offend me to see Mercury products, past or present, getting run down by an owner of a competing French Canadian product. Don't we have enough people out of work in Wisconsin already?

Tohsgib posted 01-20-2010 03:13 PM ET (US)     Profile for Tohsgib  Send Email to Tohsgib     
One more to go Larry...just one more!
Richard Quinlivan posted 01-20-2010 08:37 PM ET (US)     Profile for Richard Quinlivan  Send Email to Richard Quinlivan     
I had a 125 Merc 2+2 on a 1995 17 Dauntless Dual Console from 1995 to 2005. It idled just fine in the two cylinder mode and pulled into the 4 cylinder mode just fine. Any issues at the crossover from two to four cylinders were masked by the fact that the boat was coming onto plane through that range. I got about 45mph with a High 5 prop and a little more with a Laser II. The motor always performed just fine with no problems. It was never in the shop for any repairs. It was still running fine in 2005 when I sold it.
jimh posted 01-20-2010 10:04 PM ET (US)     Profile for jimh  Send Email to jimh     
Larry--If I have said anything in this discussion which is not true, you are welcome to please point it out.

This Mercury throwback motor might have been sold as recently as c.2005, but Mercury never updated it from its 1970's roots. I can can compare it with the 1976 Mercury motor I used to own, also an in-line four-cylinder two-cycle. There weren't any significant differences in the technology. My 1976 motor had capacitor discharge ignition, it had four carburetors, it had no balance shafts. If had a funky alarm system with a buzzer. You can say all the same things about a c.2005 Mercury 115-HP two-cycle.

Mercury never really updated this motor. Even though it was selling in c.2005 it was still using 30-year old technology. Mercury never invested in any refinements for it. No fuel injection. No Smartcraft. No PCM 555 engine controller from MotoTron. Not even an alarm system with a couple of LED's in it. It's pure 1970's technology. There are not enough transistors in this motor to make is marketable today.

I can't understand why just telling the truth is so hard to accept. It's a motor from the 1970's--plain and simple. And I mean that about what I just said as well as about the motor. It is a plain and simple motor. If you want to buy a 1970's motor in 2010, this is a good candidate.

A guy I have worked with every day for the past 25 years owns one. He's told me many stories about his repairs. He has phenomenal skill at fixing things--everything from sophisticated digital electronics to two-cycle carburetor motors from the 1970's, and this motor has kept him busy for many years.

As for 14-posts, most of them are rebuttals to L H G. I said what I said in the first post. I repeated once or twice. If I told a lie, let me know. I said good things about this motor. I said honest things about this motor.

As for seeing them on a few Boston Whaler 19-foot NANTUCKET models, I am surprised that I have to explain this to savvy and experienced boaters as we have here. The pictures all show the introductory model of the new Boston Whaler 19-foot NANTUCKET. Everyone knows that when a new model comes out, the price is extremely influential in building acceptance. The best time to buy a particular model is generally right at the introduction because the price will be at its lowest. So it is perfectly normal to see those two 190 NANTUCKET models, one at a boat show display and the other on the lot of a big dealership, equipped with the absolutely lowest cost engine that could be fitted. This is how the total price of the boat, motor, and accessories can be kept as low as possible. It is a very common practice. Show a new boat, and show it with a very attractive price. Get people interested.

ASIDE: Dell sent me a notice of a new computer model, very compact, and only $299. I went to their website to investigate. By the time I "built" myself a computer by adding a few options or upgrades--like an operating system-- the computer cost $900. Yes, the $299 price got my attention.

I also have to really laugh at L H G's introduction of the E-TEC 90 into this discussion. I think this has become a corollary to Godwin's Law:

Any discussion of a Mercury motor's shortcomings cannot go more than 25 posts before L H G mentions the E-TEC.


L H G posted 01-20-2010 11:17 PM ET (US)     Profile for L H G    
Jim, like Glen, I'm not going to argue with you any longer on Mercs. It's a waste of our time. The loop charged block on this engine was FIRST designed and offered in 1989, so your facts are wrong. That makes it a NEWER engine design than the old "throwback", unbalanced 90 degree Vee-6 block on your new E-tec 225, a casting which I believe first came out in 1985 or 1986, the last 90 degree V-6 outboard to be designed. Everybody else has given up that old idea. Evinrude is still selling 25 year old 90 degree block technology. Like you with the unbalanced 4 cylinder, I can't imagine why anybody today would buy an unbalanced V-6 90 degree either.

Actually, I have no particular interest in this engine anyway. At least Mercury to THIS supposedly obsolete block out of production. Never owned one, never liked the sound of a two cylinder idling. I guess I wouldn't like the sound of the 2 cylinder E-tecs either, another bad, old idea for modern engines in the 40-60HP range. The good ones are 3 and 4 cylinders. But I do have the 3 cylinder version of the 2 + 2 block design. Pretty good performer, especially when compared to the supposedly "modern" 90 E-tec. I like the old throwback Merc 90.

In spite of all this, I'm not laughing at YOU. Just trying to set the facts straight, as you requested. Hope all is well with you and family, and if you want to continue laughing at me, be my guest.

jimh posted 01-20-2010 11:44 PM ET (US)     Profile for jimh  Send Email to jimh     
Speaking of V6 engines with a 90-degree arrangement, I will cite the following from Wikipedia, referring to the GM 3800 V6 90-degree block:

"The 3800 was on the Ward's 10 Best Engines of the 20th century list, and is one of the most-produced engines in history. To date, over 25 million have been produced."

Speaking of car engines, the last car I had with an in-line four-cylinder engine was a 1973 FORD Pinto. That four-cylinder in-line used to shake like it was going to break the motor mounts. That engine also did not have any balancing shafts. ALL the current larger displacement L4 marine engines have balancing shafts, except the Mercury Verado, where the displacement is 1.7-liters and the stray moments are not excessive. The Mercury 115-HP 2+2 has 1.9-liter displacement. A displacement of around 2-liters seems to be the general range where balance shafts become commonly used.

Also, please note the recommended maximum engine speed of the Mercury 2+2 was 5,250-RPM. That is about the lowest maximum engine speed on any outboard in this power range. I think it is reasonable to conclude the very low engine speed is related to the design limitation with regard to vibration problems

The use of a loop induction is not at all indicative of modern technology. In a prior discussion it was pointed out that loop induction was first shown in a two-cycle marine engine in 1968, and had been used in other fields much prior to that. Ergo, loop charging is nominally 1970's technology. This is precisely the words I used to describe the Mercury 2+2. There is nothing incorrect about that usage.

Pointing out that Mercury only got around to using loop charging in this motor in 1989 does not engender loop charging as a modern technological improvement.

Please note that much earlier in the discussion I wrote very positively about how this same general cylinder and bore design was used in a three cylinder 90-HP Mercury engine with great success. I think you are neglecting those positive statements about a Mercury engine.

Also, you should not try to align yourself with Glen regarding my position on Mercury engines being beyond any range of rational discussion. Glen knows very well, as I think you do, that I have a completely open mind about Mercury engines, and that I have lavishly promoted and praised Mercury engines many times. You should recall that long before Glen owned a Verado and long before Glen formed VERADOCLUB, I was on the very cutting edge of the wedge that drove the Verado engine into the consciousness of readers of this website, and that I wrote extensively and extraordinarily positively about the wonderful L6 Verado engines. This record cannot be dismissed or overlooked, and I cannot be painted with the absurd characterization of a Mercury basher, simply because I present completely honest and (if I may say so) astute observations about this Mercury 2+2 engine.

jimh posted 01-21-2010 08:46 AM ET (US)     Profile for jimh  Send Email to jimh     
On the notion of an in-line four cylinder engine and its balance, I refer readers to two good articles, both from Wikipedia. On the topic of engine balance:

"Engines with characteristic problems include...and straight-4 using a single crankshaft..."

On the topic of balance shafts:

"Balance shafts are most common in inline four cylinder engines which, due to the asymmetry of their design, have an inherent second order vibration (vibrating at twice the engine RPM) which cannot be eliminated no matter how well the internal components are balanced."

There is also another very good article which covers both four and three cylinder engines. It notes that:

"Although three cylinders sounds odd, in fact it has a very good Primary and Secondary balance: the one piston exerting force is balanced by the other two. Since a V6 or Straight 6 engine can be seen as a double 3 cylinder engine, this explains why it is much smoother than a four cylinder engine of the same capacity and why it is used in more expensive cars where refinement is expected."

This may help explain why the three-cylinder 90-HP Mercury (which I believe uses the same piston bore and stroke) is a nice smooth running engine, but the in-line four cylinder 115-HP is not as smooth. By the way, this same effect is seen in the Verado series. The in-line six is a fantastically smooth engine, but the in-line four version is clearly not in the same league when it comes to freedom from vibration and overall smoothness of the engine.

For me, these matters are of interest because I am curious about the underlying technology and engineering involved. The notion of a brand bias plays no part. The fundamental problem of the in-line four and its lack of good secondary balance has been understood for very long time, and a solution was devised in 1911--balancing shafts. If you read the literature from other marine four-cylinder in-line engine makers, you will find they all mention balancing shafts as a refinement or feature of their engines.

Tohsgib posted 01-21-2010 10:56 AM ET (US)     Profile for Tohsgib  Send Email to Tohsgib     
Like me Pappy always sed, "If it aint Scotish...IT'S CRAP!"
brisboats posted 01-21-2010 08:24 PM ET (US)     Profile for brisboats  Send Email to brisboats     
So when a Scottish dog poops what is it? There were other inline fours in this horsepower range at the same time. Suzuki was also making a 115 hp non balanced inline four two stroke. Force had the 120hp 4 cylinder unbalanced two stroke until the late 90's. Properly tuned these motors do not act like they want to shake out of the mounts. Bore,stroke reciprocating mass and internal balance and construction also play a role in engine smoothness. To draw the line at a certain level of displacement maybe to easy.

If this 2 + 2 is the total piece of doo doo Jim claims it is then I suggest the owners bring a class action lawsuit. Jim's former steed the Pinto certainly deserved it.


jimh posted 01-21-2010 08:57 PM ET (US)     Profile for jimh  Send Email to jimh     
Brian--You just let me know if anyone tries to trash talk the 1973 FORD Pinto, and I'll jump right in to defend it. That in-line four-cylinder engine had overhead valves. I recall that because the timing belt broke one night as I was driving home at midnight and I had to abandon the car on the side of the road. I did get almost 100,000-miles out of that car, which in 1973 might have been close to the world record for a FORD Pinto. I gave up on it when some teenager ran into me in a parking lot. I traded up to a RENAULT Alliance, another small engine but this time hooked to a five speed gear box. The Alliance did break through the 100,000 mile mark, but not while I owned it. It got 40-MPG, which in the 1970's proved useful. I don't think I have owned a car with gas mileage that good since then. You see what nostalgia can do to a person?
jimh posted 01-21-2010 09:01 PM ET (US)     Profile for jimh  Send Email to jimh     
Brian--Please don't put words in my mouth. I have given the Mercury 2+2 strong praise for its good points, and mentioned its shortcomings. If that is making it out to be a "total piece of doo doo," you are being too sensitive.
jimh posted 01-21-2010 11:32 PM ET (US)     Profile for jimh  Send Email to jimh     
The 2+2 Mercury engine varies the number of active cylinders based on the engine speed. The concept of using a variable displacement engine to improve fuel economy is currently used by a few modern automobile engines, however the technique of shutting a cylinder on or off is much different. Also, modern engines do not shut down 50-percent of the cylinders like the Mercury 2+2 engine. Instead, they may shut down one or two cylinder. And more sophisticated techniques are used. The cylinder being shut off may rotate among the various cylinder, and the control technique is usually electrical or electronically based.

It is not clear to me why Mercury used a 2+2 technique in this engine. The most natural assumption would be to improve fuel economy, but I don't know if that was the real motivation. Another reason for shutting off half the engine at lower speeds might have been to create an engine that idled down to slow speeds more easily. Generally to get a two-cycle engine to reach a slow idle like 600-RPM the ignition timing has to be retarded substantially. With all four cylinders running, the Mercury engine might not have been willing to idle down to a comfortable trolling speed. Shutting off two cylinders [may have permitted lower idle speeds]. For whatever reason, the 2+2 engine tries to turn on and off half its cylinders. This abrupt change in engine displacement produces an abrupt change in power output.

The transition is usually mentioned as designed to occur around 1,800-RPM. This is a good engine speed for a transition because generally most boats are set up so that 1,800-RPM of engine speed is not a very useful region. It is typically in a transition region between plowing along and jumping on plane. Therefore most of the time an engine is not run in this range for long periods of time.

The technique of controlling cylinder operation was extremely simple, and it involves no electronics or control circuitry. The carburetors for the two cylinders that switch on and off were designed to not deliver a combustible fuel-air mixture into the cylinders until the engine speed picked up enough to begin to draw fuel from the high-speed jets. Once this threshold was reached, the two cylinder would begin to get a combustible fuel-air mixture, and they would begin to have combustion. It seems obvious that the most likely way to suppress combustion would be to hold back on the fuel. That would help fuel economy, too. It would not make sense to try to suppress combustion with a mixture that was too rich. That might tend to foul the plugs.

Speaking of the plugs, I believe they remained active all the time. There was no control mechanism to suppress spark based on engine speed. To do that would have required a few transistors, and, as you might recall, this engine has almost none. Thus the plugs kept firing all the time. If the fuel mixture were a little too rich, but still on the lean side, I imagine you could get some interesting pre-ignition situations or engine knock.

Mercury were not alone in making an engine that tried to shut off a cylinder now and then. Yamaha used this technique in a six-cylinder engine, but I believe they only shut off one cylinder in some speed ranges and then two cylinders in another speed range. That is a much less reduction in displacement, and it did not create a very big jump in engine power when it occurred. Also, I assume the control mechanism was electrical.

L H G keeps introducing the E-TEC and trying to make favorable comparisons to it. Since he opened the door, let me say a few things about the E-TEC. I would otherwise never drag the E-TEC into this discussion, but since it is already here, I will tell you how the E-TEC approaches the control of engine combustion and fuel-air mixture.

The E-TEC runs at low speeds on a stratified charge mode operation. This keeps the fuel-air ratio on the lean side. However, the engine control module periodically modulates the fuel-air ratio of a cylinder to give it a richer fuel-air mixture. And it passes this richer mixture around the engine to all the cylinders in turn. Good idea, eh? It can do things like this because in the control module there are several million transistors. Now don't be afraid. This is 2010 and it is entirely routine to use devices with more than a billion transistors in them. (Actually the computer I am using to type this has a couple of billion transistors in it, and that is just in its random access memory modules.) Of course, it goes without saying that the E-TEC has electronic fuel injection, which, of course, is controlled by the engine management module, and it is not very difficult to maintain precise control of the fuel-air mixture. I guess I should also mention the barometric pressure sensor, the air temperature sensor, the engine temperature sensor, the throttle position sensor, the engine load sensor, and others whose input is used to help optimize the fuel-air mixture.

The Mercury 2+2 has none of this stuff. It has a carburetor. There is really nothing wrong with a carburetor. Heck they still use them on NASCAR engines. And given the moderate temperatures and the close to sea level operating elevation, a carburetor can do a darn good job of running an engine. It is just that they are very difficult to adapt to electronic controls. Therefore the science of a carburetor is all in its mechanical design, its fuel orifices, its internal chambers, floats, and so on. As long as all that stays perfectly clean and in good working order, a simple carburetor can give a very good account of itself on a warm engine, in 70 to 90 degree air, at a fixed elevation like sea level. The problem comes in when some of the fuel passages become clogged or dirty, when some of the linkages lose their adjustment, when the air is cold or the engine cold--that's when the carburetor stumbles and needs help.

When owners of the Mercury 2+2 give us first hand accounts of poor running characteristics and abrupt transitions, the cause is probably related to problems with the carburetors. Keeping the fuel-air mixture to the two cylinders that are supposed to turn on and off at exactly the right ratios under a wide range of conditions probably requires a bit of luck and precise adjustment.

cooper1958nc posted 01-22-2010 04:19 AM ET (US)     Profile for cooper1958nc  Send Email to cooper1958nc     
Jimh is close but a little off. The idea behind variable displacement is NOT to achieve better specific fuel consumption by shutting off fuel to the inactive cyls; the idea is to shut off the AIR to them to reduce pumping losses.

The equation for fuel used is

F equals d ve mp rpm mix , where

F is fuel flow
D is displacement
Ve is volumetric efficiency
Mp is manifold absolute pressure
Rpm is rpm
Mix is fuel mixture in pounds per cub foot dry sea level given temp air, or equiv units

If d is reduced, you can get the same fuel flow by increasing mp (with the throttle for example)

Power as a function of fuel flow can be expressed

P equals f sfc - lf - lp , where

P is net power
F is fuel flow
Sfc is a constant of proportionality known as specific fuel consumption that itself is a function of engine design, timing, mp, rpm, mix, and some other things.
Lf is frictional and parasitic loss, generally proportional to the cube of rpm for a given engine
Lp is pumping loss, proportional to d, rpm, mp.

In the next post ill try to explain how cutting fuel but not air to certain cyls won't save much fuel and why, contrary to popular belief, opening the secondaries in a four barrel carburetor does not automatically decrease sfc, and what generally does affect sfc.

Tohsgib posted 01-22-2010 11:25 AM ET (US)     Profile for Tohsgib  Send Email to Tohsgib     
As Brian points out that the suzuki inline 4 2 stroke might have excluded a balancer, I might agree. Having owned a 140 inline 4 Suzuki(1981) it was shaky at idle but sounded like a race car, pretty cool idle. It also redlined at 5300 as Jim pointed out to reduce vibrations. Great engine though but a tad heavy and thirsty. Lots of displacement and rated at the prop which means no 140 back then could touch it.
brisboats posted 01-22-2010 01:43 PM ET (US)     Profile for brisboats  Send Email to brisboats     
Jim, Sorry I am not sensitive to this motor at all. I guess I shouldn't have used the statement a total piece of doo doo. I respectfully retract it. What I would like to glean from all this though is a further understanding of when a two stroke engine would require balance shafts.

I am not an engineer. But do know the four cycle engines used in autos have the advantage over an outboard motor in balancing. They enjoy external balancing via the pulley area by means of a harmonic balancer and at the other end by means of a larger and heavier balanced flywheel. The crankshaft can also be counter-weighted. The reciprocating mass of pistons and rods could, like a two stroke be machined and balanced internally. As for the two stroke I have no familiarity with a balance shaft.

I also have some intimate experience with very large four cylinders both with and without balance shafts. The mercruiser 3.7 liter four, my continental-teledyne 2.7, my tractors 169 cubic inch four, the Alfa 2.0 and the big 3.0 liter four in the Porsche 944 equipped with Mitsubishi licensed balanced shafts. The problem is aside from being large displacement inline fours these motors have very little in common. Each has a different refinement and signature. In arguably none have the smoothness and refinement of an inline six like in a BMW. I think there is much more to the equation than drawing the line at a certain level of displacement.

I won't bash the Pinto I think it has been rear ended enough. I did at one time drive its cousin, a 1973 Capri with the 2.0 sohc four. I really liked that car it was a German Ford but I believe shared the same motor.


jimh posted 01-22-2010 03:46 PM ET (US)     Profile for jimh  Send Email to jimh     
Brian--Yes, the FORD Pinto I had in 1973 had a 2.0-liter German engine. It really was a decent little engine, after I removed all the anti-pollution gear that was hung on top of it, and switched to a manual choke for the carburetor so I could control fuel enrichment myself in the winter.

Cooper--If you're correct then Mercury was WAY OFF. There is nothing in the 2+2 that affects the air into the shut-off cylinder, so the pumping loss could not be changed. Maybe the shut off of two cylinders was to get better idle, as I also mentioned.

cooper1958nc posted 01-23-2010 01:19 AM ET (US)     Profile for cooper1958nc  Send Email to cooper1958nc     
Well perhaps but idle speed and quality are not related to displacement and if anything more operating cylinders increases not decreases idle smoothness. Plus the transition to full displacement is well above idle speed. So we are left with somewhat of a mystery as to why bother to shut off fuel to two cylinders at low power settings, if indeed that is what is happening.
Clark Roberts posted 01-26-2010 10:05 AM ET (US)     Profile for Clark Roberts  Send Email to Clark Roberts     
This thread is going to make my head explode!
michaelinbrisbane posted 05-01-2010 06:16 AM ET (US)     Profile for michaelinbrisbane  Send Email to michaelinbrisbane     
[Revived this discussion of the Mercury 2+2 engine to change the topic to seek repair advice. This has been moved to a separate discussion in REPAIRS/MODS.--jimh]
dp2002 posted 05-01-2010 04:41 PM ET (US)     Profile for dp2002  Send Email to dp2002     
Hey Guys--I have [a] Mercury 2 + 2 on a 2002 Trophy 1802 WA. I am a saltwater guy and certainly don't have the expertise on boats and engines that you guys appear to have. What I can say is that mine has run excellent since the day I bought it. I am pretty much a weekend and vacation boater, so maybe it doesn't have enough use to run into the problems described here. In any case my experience is that it idles good, always starts right up, cruises good at low RPM (below 1700) and takes off good when the other two cylinders kick in. The boat tops out about 40, but I typically cruise at 27 to 30 when I am going some place. It's very good on gas when trolling on salt water on two cylinders where trolling tends to be speedy because of the currents.

It does have a bit back and forth between two and four cylinders at 1700 to 1750, but I don't use this range since it's not a desired range for the environment I am in. It does tend to be smokey if I use a lower grade two-cycle oil, but with low-ash oil it does good. The smoke and smell is really reduced, but oil price is double. In summary, it's been a good engine for me.

Would I buy another one? I don't know, the technology is older now and I would be moving forward. Would I not buy one at all. I have been happy with mine, but maybe I have been lucky.

It has gotten me off shore and back for years with a zero failure rate. This is not a recommendation, just my experience and a sample of one is not worth much, but all in all I have liked it.


John W posted 05-02-2010 07:53 PM ET (US)     Profile for John W  Send Email to John W     
Darrell--As I added to this post back in 2006, my father's Merc 2+2 motor has been trouble free and runs great, except in that midrange when the other 2 cylinders kick in. He still owns it, and has transferred it among several boats he has owned, now on a 17 Montauk. It is still trouble free and runs great. Glad to hear yours is working well for you also.

If you look at the postings above, you'll see that the majority of folks on here who have actually used or owned this motor said it was a good motor. "sosmerc" did not like it relative to other 4 cylinder 2 stroke Mercury's. My father's merc mechanic loves these motors. The strongest criticism of the motor is coming from jimh, who has never owned one, and I would be willing to bet, has never been on a boat with one or run one. I would guess he doesn't personally know anyone who has owned one. He claims it runs rough at high rpm, based on his conjecture, even though no one else who owned one here would agree with that comment.

In short, don't worry too much about the talk here about that model. Go out & continue to enjoy your motor.

jimh posted 05-03-2010 09:33 AM ET (US)     Profile for jimh  Send Email to jimh     
If we are all going to repost our opinions, I will be glad to repost mine. I continue to recommend against buying a used Mercury 125-HP 2 + 2 motor. There are far better choices in used outboard motor in this power range. Attempts to redeem and sanctify this motor are pure in motivation, but, as I said before, people who have a particular motor often tend to become fond of it.

I cannot imagine a situation in which if offered the choice between a Mercury 2 + 2 motor and another more conventional motor of similar horsepower, that I would choose the Mercury 2+2. For example, if offered a choice between a Yamaha V4 115-HP and this Mercury, I would choose the Yamaha. If offered a choice between an OMC V5 115-HP and this Mercury, I would choose the OMC. If offered a choice between a Yamaha V6 130-HP and this Mercury, I would choose the Yamaha. And so on. I think this reflects the general opinion of boat buyers. On the water you will see hundreds of Yamaha and OMC V4 engines for every one of these Mercury 2+2 engines.

In addition to all the reasons I have already set forth, I suspect that the exhaust gas emission from the Mercury 2 + 2 motor is higher than normal for a carburetor two-cycle outboard due to the contribution of unburned fuel from the two cylinders which do not operate at lower speeds. Until the fuel-air mixture in those cylinders reaches a ratio which supports combustion, the fuel in those cylinders is just pumped out in the exhaust emission. This likely makes the exhaust emission and subsequent water and air pollution even higher than conventional two-cycle outboard motors.

I also suspect that the waste of unburned fuel decreases the overall fuel economy of the motor compared to a more conventional motor. Fuel economy of conventional carburetor two-cycle motors at idle speed has never been very good. The motor may be worse than average. Again, this is speculative. I welcome any real data from the enthusiastic owners of this motor from which we might develop a feeling for its BSFC at idle.

Further, the Mercury 2+2 motor is no longer being made. While other classic high-emission outboard motors from Mercury's past continue to be produced, this one has been dropped. In this way, we have Mercury's own vote on this motor.

L H G posted 05-03-2010 06:26 PM ET (US)     Profile for L H G    
I know someone looking to get rid of an Evinrude V-4 2-stroke and buy a clean used Mercury/Mariner 20" 2+2, 1996 and newer. Seriously, I do. He also says they are great engines.

If anybody here wants to get rid of one of "Jim's dogs", let me know and I'll pass the information along to the non-Whaler owner buyer.

John W posted 05-03-2010 06:50 PM ET (US)     Profile for John W  Send Email to John W     
L H G, my father replaced the v4 OMC 115 hp that was on the Montauk when he bought it, sold that motor, and put the Merc 2+2 on it from a previous boat. He has owned virtually every brand of motor, and is only "loyal" to the Merc because it has been smooth and reliable. It is certainly no less fuel efficient than any other two stroke, in any noticeable way. He also owns a Yamaha 4 stroke on a different boat...this is not blind loyalty or ignorance, as jimh suggests.

I would agree with jimh in that I personally would prefer a Yamaha v4 over the Merc 2+2 all else being equal (I have owned both), but the advice that this 2+2 motor is dramatically worse than any other old 2 stroke isn't supported by many who have actually owned these 2+2 motors.

jimh posted 05-03-2010 09:05 PM ET (US)     Profile for jimh  Send Email to jimh     
I lot of words have been put into my mouth. I have said nothing about the people who have owned and reported on their Mercury 2+2 motors being "blind" or having "ignorance." Those words were not used by me. I simply said that people often become fond of their own motors. That is just human nature, it is not something startling or invented by me.

I have some nostalgic fondness for that old German-made in-line four cylinder in my 1973 Pinto, but I don't try to tell people that it was a great engine, ran beautifully, and is better than a 2010 Ford Eco-Tech.

I don't feel that I have to disqualify myself from expressing my opinion on whether or not I want to own a Mercury 2+2 motor just because I have not owned one. I don't want to own one, and that is probably why I won't own one. I clearly stated the reasons why I am not a fan of the 2 + 2 motor. So far I don't see any rebuttal, just anecdotal reports that they run and have power. I already said that they run and have power: read my first comments.

I would characterize my opinion on this motor as being realistic. Please stop trying to indict me as a basher of this motor. I just tell people the honest truth about this motor. The honest truth about this motor is that is a not-so-great example of 1970 technology, now no longer being made, and very likely for all the reasons I have given. If this were the greatest motor in Mercury's giant line-up of motors, you'd have to wonder why Mercury was so stupid to stop making it, why they never used this approach to variable cylinder operation again, and why so many people comment about the abrupt transition from two to four-cylinder operation.

The guy asked if he should buy a used one, and I told him I wouldn't. Where is the crime?

MAholendasun posted 08-17-2010 08:15 PM ET (US)     Profile for MAholendasun  Send Email to MAholendasun     
[Responding to LHG's notice that he has buyers ready and waiting to buy Mercury 2+2 motors, this author announces he has a such a motor for sale:]

I have a 1999 125 2+2. I am looking to reduce power since my son will get the boat. You have read all the comments and other than the rough transition 1800-2200 rpm, the motor runs very well, and very strong.

creg posted 09-24-2010 02:22 PM ET (US)     Profile for creg  Send Email to creg     
I have posted before about 115-HP Mercury 2+2. [Here is] an update on engine performance. Just finished up another tournament fishing season. [I have] been participating same boat and motor since 2002. Tournament fishing is tough on engines--off to WOT, hour runs WOT, excessive torque jumping wakes, shallow water idles, you name it. The 115-HP 2+2 has proven to be junkyard tough for my use--change water pump every three years, [add] Seafoam [to] gas, [replace spark] plugs every two years, annual lower unit grease change out and use 6 ounces of lucas gear lube per fill up, and go like [mad]. These motors may not have the latest technology--but I will personally sacrifice technology for dependability. You want a simple super tough engine. Get a 2+2!
jimh posted 09-25-2010 11:58 AM ET (US)     Profile for jimh  Send Email to jimh     
Thanks for your testimonial to the prowess of the Mercury 2+2 as used in competitive fishing tournaments. The type of operation you describe in which your operate the motor at either idle or maximum throttle seems to be a perfect fit for the Mercury 2+2 motor design.
creg posted 09-26-2010 04:30 PM ET (US)     Profile for creg  Send Email to creg     
Yes, on tournament (fishing) days typically engines are put to the test, that is what I was trying to to explain with the examples from idle to wide open throttle. However, every day on the water practicing or pleasure fishing does not employ the same strenuous needs from your outboard. Slow starts, up on plane and cruising,no problems there either(not to mention improved gas mileage). The transition from 2 to 4 cylinders has been way overstated, having fished with different anglers (no we don't talk about 2+2 issues all day) and its never mentioned. I'm one of the older guys in the tournament scene and what I have NOTICED is younger anglers (FOR THE MOST PART) haven't had the opportunities to work on their own motors and don't have a real good concept of whats going on under the cowling. The have been brought up in a world where everything is so technical and requires special tooling or diagnostics they are scared away and surrender to to the marine shops for even the basic stuff. I fished with a kid (finacially challenged) said his boat was at the dealer to change the lower unit grease. I told him "you can do that and save yourself a few bucks," inquisitively looked at me and said "wouldn't that void my warranty." I can only assume he was repeating what he had told. The latter is not so much related the topic but I think its important. My grandmother was a great cook, my mom not so good, my wife makes reservations, and I'm teaching my daughter to cook? I DON'T KNOW!
jimh posted 09-26-2010 06:19 PM ET (US)     Profile for jimh  Send Email to jimh     
I agree that it can be a pleasant experience to make simple repairs and adjustments to an outboard motor, and I agree that owning a Mercury 2+2 motor will give plenty of opportunity to do just that.
creg posted 09-27-2010 12:47 AM ET (US)     Profile for creg  Send Email to creg     
Do you really know if someone buys a 2+2 they will have plenty of opportunities to do simple repairs? Having never owned one, never piloted one, never worked on one or even seen one in operation, where are the credentials to be such a harsh critic and advise someone not to buy. Like I said earlier, if someone is looking for a strong running engine, junk yard dog tough, no down time, normal maintenance, decent gas milege, does not have to be returned to the marine shop for nine years, user friendly to change spark plugs, fuel filters, water pumps this a good candidate. I stand by what I say "BUY A 2+2", I know-- I own one, piloted one, worked on one and have seen more than just mine in operation. After proof reading, I think from this point on I should be the expert and you should remain the guy who has never seen one in operation. I think any action taken foward regarding the purchase of a 2+2 should be referred to me as an owner for an honest evaluation and then let him/her make up ther own mind.
jimh posted 09-27-2010 01:19 AM ET (US)     Profile for jimh  Send Email to jimh     
Creg--I am simply agreeing with you. It was you who provided all the information about the frequent adjustments and repairs you make to the motor.

I am more of a realist about the Mercury 2+2 motor than some other observers. I place more faith on the opinion of experienced Mercury mechanics such as sosmerc who said,

"I would not sell a 100, 115, or 125hp with the 2+2 system to anyone, except maybe my worst enemy!"

I have laid out all of the reasons why I am have not been able to join the fan club for the 2+2. My reasons are all clearly explained. If you believe that any of my comments are in error, you are welcome to rebut them.

The notion that only people who own and like a Mercury 2+2 motor should be eligible to comment on them is not acceptable. It may very well be that some of the more acute analysis of the motor may come from people who are actually not current owners of the motor.

Clark Roberts posted 09-27-2010 07:11 AM ET (US)     Profile for Clark Roberts  Send Email to Clark Roberts     
Well put, Creg!
L H G posted 09-27-2010 07:18 PM ET (US)     Profile for L H G    
Leftover 20" Mercury 115HP 2-2's are getting hard to find, and still command a high price.

I noticed that Sue at Twin Cities Marine has one for sale, brand new in the box, for $6200. That's only $1100 less than the price of a 2011 115 Optimax, and the 2 + 2 is 7 years old. Pretty amazing.

I'd buy that 2 + 2 in a minute, if only I had a boat to put it on!

jimh posted 09-27-2010 08:14 PM ET (US)     Profile for jimh  Send Email to jimh     
Larry--You are asking us to willingly suspend our disbelief that you would buy a Mercury 2+2 motor. I don't believe you for a minute. You have been the CHAMPION of the OPTIMAX for years, yet you have never bought one. I will believe your stance for the 2+2 when I see a pair on the transom of your boat.

If you want to talk the talk you have to walk the walk, I think the saying goes.

Peter posted 09-28-2010 07:29 AM ET (US)     Profile for Peter  Send Email to Peter     
With an asking price of $6,200, it's little wonder that the 2003 Mercury 115 2+2 is new, in-the-box and has gone unused for over 7 years!

I think we all should take up a collection effort to buy Larry a boat so that he can fufill his dream to buy the 7 year old left over Mercury 115 2+2 for $6,200. He did not say that the boat had to be a Whaler so just a couple of bucks ought to do it. ;)

rigidhulls posted 09-07-2011 01:29 AM ET (US)     Profile for rigidhulls  Send Email to rigidhulls     
I'm helping someone interested in a very clean, very low hours 1997 boat, single owner, boat with a Mercury 1997 115HP Model: 1115412TD Version: ELPTO

Good match for the boat: good HP, low weight. But the Mercury has to be as good as the boat (or close).

I'd like to hear from owners of there era of Mercury 2 stroke, 2+2 especially 115HP (which doesn't seem to invoke the same hostility as the 125HP)

This motor was relatively cheap new so it can't really be compared to a pricier brands. There seem to be the usual [problems or malfunctions] but apart from this [discussion] the only real complaint appears some of the surge some (but not all) people have experienced.

Still seems to be possible to get all the parts and this is a relatively simple engine (despite the innovation that could not compete with 4-stroke).

My own observation of the motor on this particular boat was that it was great on cold start and ran really well. No shaking (that is sometimes common on 2-strokes on idle), very smooth. Low emission and fumes (again, compared to other 2-strokes). I was impressed until I read all these post on the forum.

The boat is in near mint condition for a 14-year-old boat. The only problem with the boat is potentially this 1997 Mercury. I would have prefer to see a Yamaha. Since the motor is original on the boat, it has very low hours (100 hours). To those who have had [a Mercury 2+2 engine] since original (now 14 years), would you buy a boat with such a motor if it has less than 100 hours on it? Or is it trash enough to kill the purchase of this otherwise very nice boat?

If you still have your Mercury 115-HP with the 2+2, how many hours does it have on it and was it a good motor for you?

PS Most of us would love to have a brand new, tier one modern motor but the price is up there. This motor doesn't have to be perfect but it has to be good.

[Introduced an entirely new topic. Please start a new thread for that topic.--jimh]

jimh posted 09-07-2011 08:18 PM ET (US)     Profile for jimh  Send Email to jimh     
I do not believe there has been any change in anyone's opinion since they expressed it in this discussion, so I don't see why you can't be guided the opinions already expressed. It seems unnecessary to call for all new opinions. Opinions have already been given. I'd just read them carefully and make your own judgement.
Tohsgib posted 09-07-2011 09:49 PM ET (US)     Profile for Tohsgib  Send Email to Tohsgib     
Better be REALLY cheap.
rigidhulls posted 09-08-2011 03:19 AM ET (US)     Profile for rigidhulls  Send Email to rigidhulls     
I was really, really hoping to get first hand experiences. Not the "reported surge at 1800 rpm" type of third party opinion. Third party opinions are like third party witnesses. I'd love to see some first hand experiences. Maybe it's just with the whalers? Maybe it's an altitude thing? Maybe it's the 125-HP? I want to understand and I don't right now. I just see a few people angry at these 2+2 (hug your wifes and kids folks, don't stay angry...:)

Again, anyone with first hand experience with the "1800 RPM surge"? Google doesn't come up with much specific to this engine??!

Normally, with really bad engines, there are numerous threads bashing them. I see this thread as highly polarized but it's not supported across the boards (the net)?

The consensus I see is that these are workhorses.

And if it is a bad engine, fine, but [changes topic--again, please start a new thread to introduce a new topic--jimh]

I get that some people think the engine should have never been built. I get that. Makes sense, comes out loud and clear. No need to repeat yourself. But it's built, it's on boats, let's find solutions folks. Buy and drive to the ground or buy and repower? For the third party people, solutions please! ;-)

Tohsgib posted 09-08-2011 06:16 AM ET (US)     Profile for Tohsgib  Send Email to Tohsgib     
As Jake Blues would say...I guess your up [a] creek!

This guy is a Merc mechanic...I think he said it all a year ago.

"I'll be putting on my "flame suit" shortly after typing this......
I don't think you will like the 125 Merc. I like everything about these motors...EXCEPT THE WAY THEY RUN!!
They have been VERY troublesome for some. They are very touchy...some idle well, and others are very inconsistant.
They do not always accelerate cleanly...and around 1800-2200 RPM they can't make up their mind whether to run on 2, 3, or 4 cylinders. Once on plane and cruising, they are ok. Top end power is ok. When everything is PERFECT, they can even idle and troll OK. But RARELY is everything ok. I would not sell a 100, 115, or 125hp with the 2+4 system to anyone, except maybe my worst enemy! (on the positive side, they have brought me alot of work with all their problems)."
jimh posted 09-08-2011 07:21 AM ET (US)     Profile for jimh  Send Email to jimh     
It is philosophically consistent that people who do not strongly endorse the engine do not own the engine. For people who strongly endorse the engine but do not own the engine themselves there is a philosophic inconsistency.
stevo0429 posted 09-28-2011 03:33 PM ET (US)     Profile for stevo0429  Send Email to stevo0429     
I have a [Mercury 125-HP] 2+2 and I love it. I have never had a problem withit. It sits on a Kenner 19-foot bay boat. The power surge is not a big deal for me, but I can see how it could be on a smaller boat. At WOT [the 19-foot Kenner boat] does around 38-MPH, but I can run at 20-MPH an, probably down to 14=MPH before the power drops. It is cold natured, so I usually warm it up at home before I get to the ramp. Other than that it is a great motor.
creg posted 09-29-2011 03:22 PM ET (US)     Profile for creg  Send Email to creg     
Just took a peek to see how things are going: not a lot of action on the old 2+2. It [has] been about a year since I posted. The old black beast 2002 115-HP is running strong. Maintenance consist of new fuel filter, Seafoam each fill up, no [blended ethanol-gasoline fuel], set of plugs, lube accelerator pump shaft, lower unit grease. Estimated fifty outings. This baby is running on a shoestring budget. I stick by my [recommendation]: if you want a tough, strong, runner, simple engine with low cost ownership, own a 2+2.
jimh posted 09-29-2011 09:58 PM ET (US)     Profile for jimh  Send Email to jimh     
I would modify creg's recommendation:

"If you want a tough, strong engine with low cost ownership, own [any modern outboard motor]." Follow my recommendation and you can shed the following problems, which I also have mentioned before:

--rough idle
--rough running
--bad fuel economy
--hard starting
--high emissions

creg posted 09-30-2011 03:38 AM ET (US)     Profile for creg  Send Email to creg     
Rigidhulls--like buying anything used beware whether it be boats, trains or airplanes. After that being said, I would personally do a compresion test on all cylinders, make sure side plates (water jacket covers) and head cover plate
bolts havent been removed. You can tell because engine is painted after assembly and any scuffed or missing paint would suggest the engine may have been over heated. Also after boat has set drop a little grease out of lower unit to make sure no water has gotten inside of housing. If this is the case water may drop out of drain hole or grease may be milky looking. If it runs out well as stated I would without hesitation recommend to buy. Don't let someone who hasn't owned one of these motors scare you guys off. I have had nothing but great sucess with my 2+2. The surge between 1800 rpm to full throttle is neglegible, you just power through it to cruising speed. My 115hp starts right up and idles smoothly,I have only done rountine maintnance and probably spent $200 to $300 in 10 years. If your friend does decide to purchase I think it would be advisable to change out the water pump if it is original. Sounds like a fair deal to me, hook up with the old girl and have a lot of fun; I know I have.
creg posted 10-03-2011 02:28 AM ET (US)     Profile for creg  Send Email to creg     
Rigidhulls, went back and reread your post. I dont have an hour meter for actual run time but I can give you some information that will probably get us close. Over the course of ten years I would average 60 outings annually, actual engine run time would probably average 2 hours each outing. We are fishing during the course of eight hour days, alot of times youre on the trolling motor but I think 2 hours per trip would be a good average. So the math: 10 years X 60 trips annually= 600 total trips X avg 2 hour run time= 1200 total hours run time. I dont know how many hours typically these 2+2 go--mine is running as strong as the first time out WOT 5200rpm gps speed 49 mph. I think alot of these engines get a bad rap because they are not set up properly prior to delivery. Our mechanic went through tech book adjusted linkages, carb adjustments, retimed, synched accelerator pump before the dealership would release boat for delivery. You turn the key and this baby barks. Hope this info may help you and your bud make a sound decision.
Peet posted 02-13-2012 10:57 AM ET (US)     Profile for Peet  Send Email to Peet     
[Revived this thread only to completely change its topic. Article deleted. Start a new thread to change to a completely new topic--jimh]
dfelkner posted 03-19-2015 08:11 AM ET (US)     Profile for dfelkner  Send Email to dfelkner     
[Began a new thread six years after this thread began in order to discuss this thread and offer rebuttals. The fervor of the few owners with surviving engines of this design is impressive. As a special accommodation to this author, I have moved his comments to this thread, even though it has been closed and dormant for years-jimh]

I own a 2002 Mercury 125 2+2 motor. My motor starts perfectly. I just took it out for the first time this year and it started on the first hit. It idles perfectly, never misses a beat. It does not smoke at all. Smoking is not an issue with the engine in the first place, it is the oil you are using. I use the motor for a lot of trolling. It does a great job. I have not noticed the fuel consumption to be any higher than other outboards I have owned unless I am running at 4,000-RPM and above. Below 4,000-RPM it is very economical.

Many have commented about it not having balancing shafts and it vibrates too much. I have never noticed excessive vibration. In fact, it does not vibrate as much as my friend's 1987 Evinrude 150.

There is a small transition from 2 to 4 carburetors at 1,800-RPM which makes it hard to stay on plane at 20-MPH, but a few MPH less or a few MPH more fixes that problem; this is not an RPM range I normally use. I idle and I cruise around 3,000-RPM.

My outboard is now 13-years old. I have not experienced any major repairs. In fact, I have not done hardly anything to this engine except for replacing the voltage regulator wiring plugs with butt splices. I have rebuilt the fuel pump, and I have put new float needles in the carbs.

Overall I find it to be a very good outboard and I plan on keeping it for many years to come.

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