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Author Topic:   4-strokes or 2-strokes
roccus posted 03-04-2002 07:21 PM ET (US)   Profile for roccus   Send Email to roccus  
I've recently purchased a 1969 Nauset that I intially thought I'd repower with a 80-hp Yammi 4-stroke - until I saw the weight, 356 pounds. A 70-hp Suzuki isn't much better, weighing in at 335 pounds. From what I know, that's too much for that 16' 7" hull.
A 90-hp 2-stroke Yammi weighs 261 pounds; a 70-hp 2-stroke is 228. Nice engines, but they're not 4-strokes.
A 60-hp 4-stroke is 244 pounds, plenty light but I wonder whether that's enough ponies When the conditions are right, I'd like to be able to run.
I'd appreciate any advice.
JBCornwell posted 03-04-2002 08:23 PM ET (US)     Profile for JBCornwell  Send Email to JBCornwell     
Hi, Roccus.

I have a Suzi DF70 on my 16'7" Montauk and am very happy with it. I definitely wouldn't go any heavier. It is faster than I require, WOT 38.5 GPS mph.

If I were shopping for the Montauk today, the Merc EFI 60 or the Suzi/Johnson EFI DF50 would probably be my first choices. I would expect WOT to be around 30-33mph.

Red sky at night. . .
JB :)

Tom W Clark posted 03-04-2002 08:33 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     

Don't let the motor's weight worry you. Anything under 400 lbs will be just fine.

roccus posted 03-04-2002 10:46 PM ET (US)     Profile for roccus  Send Email to roccus     
Thanks for the feedback. I'm leaning toward the 90-hp 2-stroke but still intend to do some more homework.
vdbgroup posted 03-04-2002 11:01 PM ET (US)     Profile for vdbgroup  Send Email to vdbgroup     
Go for the Yamaha 90.

It is fuel efficient, light, and fast, when you need it. Also, light on wallet.

Don't forget to consider hole shot characteristics of motors.

PMUCCIOLO posted 03-05-2002 06:20 AM ET (US)     Profile for PMUCCIOLO    
I powered my recently purchased 17' Alert with a 90HP Yamaha. The boat planes immediately with almost no bow rise, acceleration (from idle or while on plane) is great, and fuel economy is satisfactory. It cruises well at about 3200 RPM's, with a top engine RPM of 5300. I'm waiting until it's fully broken in and off double oil before measuring speed and fuel consumption to calculate economy figures. If you have any specific questions, feel free to let me know. If it were up to me, I'd certainly select the same engine again.


triblet posted 03-05-2002 09:53 AM ET (US)     Profile for triblet  Send Email to triblet     
I've got '97ish Montauk with an Evinrude 90HP
two-stroke (336 pounds IIRC). Works just fine.
Top speed about 41 MPH (just me and a couple
of gallons of gas). Pulled Big Paul (probably
240 pounds) up on a single ski no sweat.

But if I were to repower today, it would be
a 70HP four stroke.


Bigshot posted 03-05-2002 10:34 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
Like JB & Givisko, I have the 70 Zuki on a 6" jackplate. I replaced my 90 Yamaha. I am hitting almost 39 and my Yamaha did "Maybe" 42. 3mph aint nothing unless racing. I would not trade that 70 zuki for 2 yamaha 90's after running it around.....soooo quiet. Look at my performance posts etc on this site.
gunnelgrabber posted 03-05-2002 12:59 PM ET (US)     Profile for gunnelgrabber  Send Email to gunnelgrabber     
"big" et al,...your setup sounds great.i wonder though does anyone know if the demise of the 2 stroke yam 90 hp is coming? or, are all 2 strokes to be phased out in the near future? and do the nice quiet 4 strokes have the life and durability? have they been here long enough to be compared to the tried and true omc v4s?...lm
Bigshot posted 03-05-2002 01:38 PM ET (US)     Profile for Bigshot  Send Email to Bigshot     
Probably the last year maybe another for the 90. Great engine....especially on a 17' due to it's light weight. In all honesty you will be disappointed in it's performance compared to a v4. I would consider the 90 a 80hp so compared to a 70 it aint too far off. I also think the 70 Zuki is a bit more powerful being I don't think a 70 Yamaha will keep up with it.
lhg posted 03-05-2002 07:10 PM ET (US)     Profile for lhg    
Both Yamaha and Mercury have indicated they will be selling the highly popular conventional two strokes right up through 2005 model year. In 2006, they are banned.
roccus posted 03-05-2002 08:11 PM ET (US)     Profile for roccus  Send Email to roccus     
Thanks for the info.
I wonder whether the Suzukis are as "durable" as the Yamahas. I've had great luck with a 3-cylinder 30-hp Yammi (14 years old and still purring)on an old lobster skiff. Do you guys feel a 70-hp is a better fit than a 90 for an older Whaler? And does that 70-hp Yammi stack to the 70 Suzuki in terms of performance? Thanks.
marc monreal posted 03-05-2002 11:45 PM ET (US)     Profile for marc monreal  Send Email to marc monreal     
Roccus and Bigshot, I have an early 90s Yammie 70hp rigged on a 6" Springfield jackplate set 2" up and am turning 13.25x17" rapture ss prop. With this rig at WOT I get 39.2 mph per gps and am at 5800 rpm. I get good fuel economy and the handling is great. Just returned from catalina island today, round trip was about 50 mi and didn't come close to burning one of the 13 gallon tempo tanks. Got to love the weather in Ca. this time of year. If I were to re-power I would definitely consider one of the 4 stroke 70's out there due due to the high praise they are geting from some of the highly knowledgeable charecters on this forum. Still the 70 Yammie is a great engine for the Montauk. My .02
Regards, Marc
Bigshot posted 03-06-2002 10:13 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
Great info. Marc. Most I have heard people here claiming 35-37 with the Yammie 70. The 70 OMC seemed to do a bit better. I assumed it was due to smaller CID just like the 90 Yammie can't compare to a 90 OMC as far as overall grunt. Don't get me wrong...I love those yammies, especially that 90hp. But I have to say I would never go back to a 2 stroke again unless it was a Merc racing engine like the 300promax, etc.

LHG I thought 2004 was the last year so I assumed 2003 would be the end. I know Yammie stopped with non-oil injected 90's this year so they are priming up for stricter laws.

Whaletosh posted 03-07-2002 08:52 AM ET (US)     Profile for Whaletosh    

One thing to consider is your location. Are you in California? You might as well get the four stroke or accept the fact you will be limmitted in your boating choices. Can you even buy a non DFI two stroke or a four stroke in California.

Have you considered looking for good used motor? Not all of them are trashed. You might check with some dealers to see there stock, also try traderonline. You might find a rebuilt one that comes with a warranty.

Begin soapbox:
If I were in the market for a new outboard I would not get anything but a DFI two stroke or a four stroke. California won't be the only place to institute bans on boats with "dirty" motors. If one were to buy a conventional two stoke now and in just a few years one is suddenly unable to use said motor where one wants what are the choices. Keep the motor and put up with the hassle, which will only get worse. Sell the motor, yet what would the motor be worth at that point. Saving a few dollars now could prove to very costly in just a few years. This is purely speculation on my part. I wouldn't gamble on "they won't do it here".

end soapbox

JBCornwell posted 03-07-2002 09:41 AM ET (US)     Profile for JBCornwell  Send Email to JBCornwell     
Hey, Roccus.

I'd like to divert you just a little, from 2 vs. 4 to how much power.

I have just recently begun acquiring pre-1980 Whaler literature and have been reminded that, even in the days of crank-rated hp, 16/17 whalers were commonly powered by 50-55hp engines. Those engines would rate at 40-45hp by todays system.

Further, we have lower ends with much less drag and much more efficient props.

When I bought my first Whaler in 1966 I put a "100" hp Johnny on it. It seemed VERY fast. When I repowered it with a 70 looper in '80 it seemed just as fast.

I had a 17 with a teen girl in it run right alongside me last summer at 35mph. She had a Suzi DF50 on it.

My point is that 70-90-100hp are NOT necessary for good performance in a 17. They require more weight and more fuel, and more bux, to go a little bit faster.

Red sky at night. . .
JB :)

Bigshot posted 03-07-2002 10:05 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
This topic(in general) is getting old. This is the same debate as stick shift vs automatic. Automatics are smoother, cost more, heavier and slower in performance. Which do you prefer? Do you drag race constantly so that .3 seconds in 0-60 mean that much? Do you nail the throttle to the dash every holeshot and run wide open constantly. If you drive like that then a 4 stroke will probably not suit your needs. If you don't 4 strokes outweigh the 2 strokes in positives in my book. Until you run one....this debate will last forever.
Salmon Tub posted 03-07-2002 07:44 PM ET (US)     Profile for Salmon Tub  Send Email to Salmon Tub     
JBCornwell, I agree with the fact that you don't need a massive amount of horses on a 17 but I had a 40 on mine, and though enough to do the job, I lacked one thing, weight. The boat sat bow low and rode that way too. made it very bumpy. mileage was good, but i actually have the same consumption now with my 90. Plus it sits better in the water. My 40 was 165 lbs, the 90 is 300 lbs. I've actually seen guys with twin 40's in my area, but though it looks neat, there are some disadvantages.
roccus posted 03-08-2002 09:04 PM ET (US)     Profile for roccus  Send Email to roccus     
You guys have certainly given me some stuff to chew on. I wouldn't hesitate for an instant of going with a 4-stroke other than the weight - I've got to believe that an 80- to 100-pound difference on the transom of a boat this light is going to have an impact, and not necessarily for the better. I'm certain a 50 would be fine if it was just me in the boat all the time, but I don't think it's going to give me what I need when the occassional trio of 180- to 200-pounders is on board. For now, I'm leaning toward a 2 stroke, which I suspect will be grandfathered in in terms of emissions for a fair amount of time in most areas; California is the predictable exception.
jimh posted 03-09-2002 07:59 AM ET (US)     Profile for jimh  Send Email to jimh     
Outlawing use of existing 2-stroke outboards on a nationwide basis would probably create more pollution, not less.

There would be mountains of perfectly good, working outboard motors that would have to be thrown out. Maybe they'd get recycled. Maybe they'd end up in land fills.

Even if there was zero impact from disposal of all these old engines, there are other problems with bans.

Right now, today, 4-stroke engine production is having trouble keeping up with demand. A Mercury dealer told me yesterday that quoted delivery times for 4-stroke engines had just jumped to 4-weeks. He is telling customers they better order soon if they want an engine delivered by summer.

There is no way engine builders could increase production of 4-stroke and low-emission 2-stroke outboards to supply the demand that would occur if use if existing non-pollution-compliant outboards was suddenly banned on a wide scale. People would be waiting for years to get an engine!

Then what? The entire population of boaters in the United States just bought an outboard. What kind of sales volume can you forecast for the next year?

Many of these "ecology" proponents don't give much consideration to other factors.

mbking1 posted 03-09-2002 09:28 PM ET (US)     Profile for mbking1  Send Email to mbking1     
I just put a four stroke Merc 60 (YAMMI in Black) on my 99 Montauk. I love it! Very good on fuel, more than adequate out of the hole, and appears to be an excellent balance as well. Many thanks to Admiral Clark Roberts of Spruce Creek Navy for his valuable suggestion.
dgp posted 03-10-2002 06:03 AM ET (US)     Profile for dgp  Send Email to dgp     
Just to give credit where credit is due, the Mercury 60 HP four stroke is 100% Mercury designed and manufactured, both powerhead and lower unit.
bdb posted 03-10-2002 08:22 AM ET (US)     Profile for bdb  Send Email to bdb     

Can you supply us with any more info as to how that 60 performs for you? Objective or subjective.

Thank you

marc monreal posted 03-10-2002 09:30 AM ET (US)     Profile for marc monreal  Send Email to marc monreal     
With all this talk on 4s vs 2s and recently having the chance to use a friends Montauk powered by a 90 4s Sukie I too am considering a change over to a 4s. My question is would I be able to use my existing harness and control box if I went a Merc 4s, considering that the 75, 90 & 115 Mercs are Yammies in black disguise. The reason for considering the Merc over the Yammie is due to a consierable cost differential. I have always had Yammies with the exception of one Merc and don't want to be disapointed. All thoughts welcome. Thanks, Marc
Kelly posted 03-10-2002 11:00 PM ET (US)     Profile for Kelly  Send Email to Kelly     
I think one of the biggest question marks about buying a new 2 stroke now is how long will the manufacturers support the out of date engines with parts. I expect that parts will not be available from the manufactures for as long as they have been on previous models. Somebody will provide parts for these motors, but availability will not be the same.

Regarding bans on 2 strokes after 2006: Like it or not, right or wrong, envirionmentally sound or not, I think you can count on it. It will start with "environmentally sensitive bodies of water"(and what body of water isn't), and the movement will just grow from there, partly supported by new converts that have experienced the benefits of the 4 stroke. By the time all new 2 strokes have been moved out of dealer inventory, the manufacturers themselves will be calling for the ban(maybe not in public).

Regarding production, I don't think that will be an issue by 2006 or sooner. I think one of the reasons production is not up to demand for 4 strokes at this point is that manufacturers under estimated demand.


masbama posted 03-11-2002 12:11 AM ET (US)     Profile for masbama  Send Email to masbama     
We will see just how long these 4 strokes hold up. You take an engine like that and put it in salt water and see what happens. As far as being "green"; how many four stroke owners are going to dump the oil down the sewer when they do the oil changes?
Whaletosh posted 03-11-2002 01:58 PM ET (US)     Profile for Whaletosh    
I for one have never dumped ANY oil, antifreeze, trans fluid, brake fluid, paint, or other chemicals down the drain, toilet, or sewer. I take all of my used motor oil to a recycler.

I understand Jim's logic about the supply of 4-strokes. I also understand his point about the sheer stupidity of banning perfectly good motors; especially all of the pollution that is going to be generated in making and distributing the replacement motors. But, since when did logic enter into the mind of a politician?

Let's look at an example. PWCs in national parks, including Sleeping Bear National Lakeshore. I know that some of us use and like PWCs, some of us hate them passionately (so let's not start yet another PWC ban debate). The reason PWCs were banned is that they are "noisy" and pollute. This is simply not logical. PWCs are not noisier or pollute more than many other boats. If a ban were truly needed based on noise and pollution, then a standard that included all of the offending boats should have been used, not just PWCs. So the only conclusion that can be drawn is that PWCs were targeted for other reasons, namely they were an easy target. PWCs are disliked (even hated) by many people including other boaters. The logical conclusion is that PWC bans are the first to come, others will follow. Count on it.

Which brings me to my point. It is no longer just a simple matter of choosing a motor solely on the basis of performance, price, weight, etc. Engine technology will be used as a tool to limit oneís access to the water. Like it or not this factor must be considered. These regulations may move in faster than we think. It didnít take an act of Congress to ban PWCs in national parks; that decision was made very quickly by the NPS bureaucracy, it was only a matter of months.

lhg posted 03-11-2002 04:19 PM ET (US)     Profile for lhg    
Sean - PWC's have been banned primarily because of the reckless way so many are driven, and because there ARE so many, and where they are driven (into shallows, etc). there is no question that people do hate these things in large numbers. But they ARE worse polluters than than equivilent outboard 2 stroke, primarily because they are 60% less efficient, requiring 2-3 times as much HP & spent fuel to move the same boat at the same speed.

I understand that 8 hours on a 2-stroke PWC puts out as much air pollution as 100,000 miles on a passenger car.

Other boat bans will not come unless they are causing problems with the environment or loss of life, like the PWC has. In protected waterways around large populations, the go-fasts are also being slowed down and required to have mufflers. Catalytic converters are also being required which will further tame them down. Most see all of this positive, and not evidence of Big Brother. Those scare tactics of the PWC industry are just that, and incorrect visions of the future. All of us can eventually live with 4-stroke outboards and DFI's. But as with autos, the current 2-strokes will be grandfathered. Hopefully, our Boston Whalers will not become hated by the general public and law enforcement, like the PWC, and therefore not banned!

Regarding the price of entry or participation in an activity, this is nothing new in the history of the world. Money has always been the deciding factor in participation in an number of recreational activites, including Boston Whaler ownership, especially new Boston Whalers. I'd like to go to the space station for a vacation, but I don't have the 20 Million to pay to the Russians right now.
Snow skiing is certainly not available to all because of it's high cost.

So if the cost of clean outboards reduces the accessiblity of our waterways, so be it. Actually, by looking around, it might be good! Things are getting crowded these days.
Looking back to my earlier days of boating and fishing, when fish were plentiful, PWC's didn't exist, and the waterways weren't clogged with boats, I find those to be pretty good memories.

Salmon Tub posted 03-12-2002 03:03 PM ET (US)     Profile for Salmon Tub  Send Email to Salmon Tub     
In regards to Jimh's post regarding mounds of perfectly good 2-strokes, In California, you can still use your 2 stroke till it dies, you can even move to Calif. with your boat and 2001 or newer 2-stroke on the boat and use it here legally, except for waterways that dictate otherwise. What I want to know is the following, can you convert a 2 stroke to DFI? Are say the Optimax engine blocks different that the 2 strokes of same HP? and what is different - intake (obviously), exhaust? On my nissan, the only difference seems to be the intake system and the computer. Block is the same. All outer dimensions are the same, cowels are inter-changeable, so what gives? I asked the dealer and they said their are a whole bunch of things that are different, but exactly what? In however many years from now, I will want (need) to repower, and will opt to put DFI. I was told that the system conversion is possible but not worth it. But no-one will give a clear answer is it impossible or unfeasable? All those guys who run 70 and 90 yamahas, mercs, johnson and evinrudes, that will have their engines rebuilt, I am surprised no one offers new 4-stroke powerheads that could fit in there. If your engine goes in the car, you don't change the whole powertrain. I am sure there are machinshops out there that could build 4-stroke blocks for these outboards, i.e. ones that would fit in the existing cowels. Heck if there is clearance, they could even make a new larger cowel. Have a machinist custom make 1 block for you and it will cost a fortune, have them start to mass produce, and may be more worth while - only question would be legal - patents... Just a thought.
Salmon Tub posted 03-12-2002 03:14 PM ET (US)     Profile for Salmon Tub  Send Email to Salmon Tub     
Sorry, just read my above post, and saw a lot of bad grammar and so on, I mean to convert Carb system to DFI, and on Nissans they call it TLDI. Sorry for the lack of proof reading, but the general idea is the same.
Kelly posted 03-12-2002 03:52 PM ET (US)     Profile for Kelly  Send Email to Kelly     
I think the Tohatsu TLDI system requires an oil pump and an air pump along with theother components. It is my understanding that the Tohatsu does use the same block as their old 2 stroke.

Came across this artile about this subject and thoughtit was interesting.

Whaletosh posted 03-12-2002 04:46 PM ET (US)     Profile for Whaletosh    
As I stated, I didn't want this to degenerate into yet another pro/con PWC debate. So this will be my last post on this subject.

You made my point. PWCs were banned for all of the reasons you stated. The problem is that those same reasons can be applied to your boat. Think it won't happen? Use google to search for the datails on the bans that are already in place on Lake Tahoe for two stroke motors, which includes the units on the back of your 25 Outrage. The same logic was used for banning these motors. There weren't any "grandfather" clauses to exempt existing motors. People have two choices; replace the motor or stay off the lake. This hasn't affected just power boaters. There were many sailboaters that had small outboards for manuvering around the marinas, coves, and channels. The sailors got the same treatment; replace or remove the motor or stay off the lake.

Don't be so sure that the Blue Water Network won't come after you next. Taken right from Blue Water Network's website:

"Bluewater has grown substantially since then, but this campaignís goal has remained the same: the elimination of two-stroke engines from all marine environments."

Not just PWCs. Don't rely on the "public" to listen to reason; they'll do whatever the media tells them to. The cost to you to swap out your motors won't matter one bit. After all "isn't it worth it". Perhaps you should remember that if you find yourself unable to afford to continue boating. I'll bet that people in large cruisers, yachts, and sailing craft used to make comments about all of those pesky outboard boaters; lamenting the "good old days" before Ole Evinrude mucked up the works
with a motor that made boating more accessible to the masses.

Check out the contrversy regarding boat acces to Isle Royal. Hasn't happened yet but the NPS is making noise about resticting access of private boats to this park, sail and power.

Re-read some of the supporting documents regarding the PWC bans. PWCs send 30 % of the gas/oil mix out as unburned pollution. That is true for many 2-stroke motors, not just PWCs. PWCs usually have noise levels of 75-85 dB, there are a lot of boats that are louder than that.

So you are right, PWCs weren't banned because of noise and pollution. They were banned because they are unpopular, and hence easy to target. I hope for your sake, and every other non-DFI 2-stoke owner, that when non-DFI two strokes are targetted that you do get the "grandfather" clause you believe will be included. Just don't count on it. It didn't happen on Lake Tahoe.

Bigshot posted 03-13-2002 11:03 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
Demand is high but not crazy as dealers tell.

I have seen more than a few 100hp Yammies from 2000 + 2001. Just saw one this weekend for $6195(in NJ).

My 70 was a 1999 leftover. In some areas dealers are on backorder but don't let that ffol you into paying list, etc.

SuburbanBoy posted 03-13-2002 03:13 PM ET (US)     Profile for SuburbanBoy  Send Email to SuburbanBoy     
The link provided by Kelly provides some interesting insight into the 2-smoke vs. 4-stroke controversy. Honda and others claim the life of a 4-stroke is TWICE that of a 2-smoke. (Reminds me of my past life, re-ringing 2-smoke dirt bikes twice a year). The price difference between 2 vs. 4-stroke begins to evaporate with the longevity predictions. I am still comfortable with my recent 2-smoke purchase, but if I had a larger hull, I might have made a different choice.


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