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Author Topic:   Mercury versus Yahama 90HP 4-stroke
Donzi posted 05-28-2015 08:27 AM ET (US)   Profile for Donzi   Send Email to Donzi  
I have 2003 Boston Whaler Montauk and would like to upgrade to a new 4-stroke fuel injected 90HP motor. Which is more reliable and better all around, a Mercury or a Yamaha? Since I currently have a Mercury on it now, I realize there are additional conversion costs going to a Yamaha.
Thanks for your input,
Jefecinco posted 05-28-2015 09:47 AM ET (US)     Profile for Jefecinco  Send Email to Jefecinco     
I don't believe there is any factual information on which is the superior engine. Both are probably excellent performers with superior reliability.

Which is better, Ford or Chevrolet? Which is prettier, gray or black?

I would choose based upon the availability of a dealer with an excellent reputation for after sale service first and total out the door price second. Noise level could be a factor all other things being equal. If you like to do your own service work ease of access to service points could also be a minor consideration.

Differences in weight are probably unimportant on your Montauk. Fuel burn differences are also unimportant unless you are a commercial waterman putting hundreds of hours per year on your engine.

If it was me I'd be looking very closely at an Etec.


Donzi posted 05-28-2015 10:32 AM ET (US)     Profile for Donzi  Send Email to Donzi     
Thanks for your input Butch. I have had great luck running Yamahas and Evinrudes on pontoon boats so that is why I was leaning towards switching to something else on my Montauk.
jimh posted 05-28-2015 11:38 PM ET (US)     Profile for jimh  Send Email to jimh     
Mercury has just come out with a new line of engines in their FOURSTROKE series, and one of them is a 90-HP. This new 90-HP FOURSTROKE is now the fourth model that Mercury has sold with the same model designator, so it can be confusing to talk about a "Mercury 90-HP FOURSTROKE", and, since Mercury no longer has model year designators, it can be confusing to try to identify the engine by a model year.

The engine I want to direct your attention to is the latest model, being made for the first time in c.2015. This latest model of the Mercury 90-HP FOURSTROKE is based on the same approach that Mercury introduced five years ago in what everyone still calls "the new Mercury 150 FOURSTROKE." The approach is to use gigantic displacement to get decent performance. And to provide some help for owner do-it-yourself routine maintenance by having intelligent design of the oil filter location, dipstick location, and fuel filter location.

This c.2015 production epoch Mercury 90 FOURSTROKE is a new design using a 2.1-liter displacement and a four-cylinder in-line block. In the 90-HP engines there are two gear case designs available. A larger than normal gear case is called the COMMAND THRUST GEARCASE. The absolute lightest weight for this engine is probably in the 20-inch shaft and regular gear case, which is specified as 363-lbs. If you get a longer shaft, the larger gear case, or both, the engine weight probably increases by 5 to 20-lbs, or to a total weight of about 370 to 380-lbs. The height of the engine cowling has also been significantly reduced from the prior generation models, returning the proportions of this 90-HP toward more normal size for the horsepower. And the transmission in the gear case has a new designed, so perhaps it won't have that familiar CLUNK when shifting. I don't know what the warranty might be on this model. I couldn't find in the brochure. Warranty has become something of a marketing tool, so the warranty might depend on when you buy it, what promotions are in effect, what state you buy it in, and other factors.

This engine is quite new on the market. I do not recall any mention of anyone having re-powered a Boston Whaler boat with this engine. I have no idea how its durability, quality, and reliability may compare to a Yamaha engine. I don't have any idea on comparative costs, but based on the existing paradigms, it seems like Mercury usually tries to compete on the basis of lower price, so I expect that its cost may be lower.

I don't know how much of your c.2003 engine rigging will be directly adaptable to this new engine, but I suspect that there may be compatibility. If the 12-year-old rigging--the remote controls, the electrical harnesses, the ignition switch panel, the safety lanyard, the gauges, and the warning alarms--are all in good condition, you may be able to use them with this c.2015 engine and save money.

I don't have any first-hand experience with this engine. In fact, I have never seen one. But I thought I ought to mention it, in case you were not aware of this recent new model Mercury 90 FOURSTOKE.

Donzi posted 05-29-2015 09:19 AM ET (US)     Profile for Donzi  Send Email to Donzi     
Thanks again Butch for the detailed message. When I bought my Montauk, I was surprised my 2003 Mercury 90hp had 4 carburetors instead of being fuel injected. I knew at some point I would be upgrading and now that time has come. I will take another look at Mercury.
jimh posted 05-29-2015 11:00 AM ET (US)     Profile for jimh  Send Email to jimh     
DANNY--If you read Butch's comments, he suggested an Evinrude E-TEC. I am not sure how you came to the conclusion you ought to take a second look at Mercury based on Butch's comments. I think Butch was suggesting you widen your choices from just Yamaha and Mercury to include Evinrude E-TEC engines.
Donzi posted 05-29-2015 11:19 AM ET (US)     Profile for Donzi  Send Email to Donzi     
Which one would shift the smoothest? My 2003 90hp Mercury 4-stroke clanks when I put it in gear and the mechanic who drove it said it is normal. I have a 2011 70HP Yamaha 4-stroke on my pontoon boat and it runs really quiet and shifting is really smooth.
jimh posted 05-29-2015 11:41 AM ET (US)     Profile for jimh  Send Email to jimh     
DANNY asks:

Which one would shift the smoothest?

I am not sure what field of choice you are asking about. Which one of what choices?

My 2003 90hp Mercury 4-stroke clanks when I put it in gear...

That description is typical for the Mercury gear case of that era. The amount of CLUNK or CLANG that occurs is also affected by the type of propeller-to-propeller-shaft connection being used. If you have a Mercury FLO-TORQ hub kit, they often enhance the loudness of the CLUNK or CLANG that occurs when a Mercury outboard engine is shifted to FWD from NEUTRAL.

Donzi posted 05-29-2015 01:32 PM ET (US)     Profile for Donzi  Send Email to Donzi     
In terms of a new model 90hp 4-stroke, would one of these brands generally shift smoother than the others?
1. Evinrude
2. Yamaha
3. Mercury
4. Honda

Thanks for your input,

jimh posted 05-29-2015 04:45 PM ET (US)     Profile for jimh  Send Email to jimh     
I do not know of any good investigation into the amount of noise made when shifting that has been done on any controlled basis using a calibrated measurement of the sound pressure level produced. Any observations would be primarily anecdotal. It is difficult to make accurate statements about the comparative loudness of two sounds made by ear by a human listener due to the lack of very accurate aural memory for loudness when the two stimuli are presented with an interval of more than ten seconds between them. Sure, you can remember that a jet engine at a distance of 100 feet is louder than a gentle breeze rustling in the trees, but it is unlikely any human observer could give accurate accounts of comparative loudness of the shifting of gear cases, unless the sounds could be compared at very short intervals.

I can offer you only this anecdotal observation. I have an Evinrude E-TEC with the ICON electronic throttle and shift option (ICON EST). The gear case shifts are very precise and to the best of my recollection produce no noticeable CLUNK or unusual noise.

I do recall hearing a fellow with a Boston Whaler 170 MONTAUK and a Mercury 90-HP outboard--probably one from c.2003 which would be the model like DONZI's--make a shift while at a fuel dock adjacent to where my boat was. The CLUNK of the gear shifting was so loud it was startling, and, as evidence of this, I can still remember that happening.

I believe that one of the claims made by Mercury about their newest model of 90-HP FOURSTROKE is an improvement has been made in the gear case to create smoother and perhaps quieter shifting.

Improvement in the smoothness and reduction of the CLUNK was one of the goals in the development of the Mercury FOURSTROKE VERADO engines. At the time the VERADO was being brought to market, c.2002, even the head of Mercury engineering remarked that their older engines had very loud shifting and sounded like a "1950's truck." Perhaps some of the refinements made in the VERADO have been carried on to the new 90-HP FOURSTOKE.

Quoting from the Mercury brochure about the newest 90-HP FOURSTROKE:

New Clutch System
Every time you shift into gear, the new clutch
design delivers reduced shock and vibration,
another contributing factor to our industryleading
smooth performance.

You should note that Mercury has declared their new clutch to be leading the industry in smooth performance. On the basis of that declaration, I believe you would have to give Mercury first place among all outboard brands in smoothness of shifting. Leading usually means being in first place.

Also from the brochure:

Mercury’s hemi-anechoic chamber enables
our engineers to analyze and optimize sound
quality in order to achieve world-class noise,
vibration and harshness (NVH) levels in our
outboard engines.

Again, Mercury has declared that the level of noise, vibration, and harshness in their engines is "world-class." According to M-W.COM, the phrase "world-class" means "among the best in the world." On the basis of that declaration I believe you would have to give Mercury a ranking of the same as the best of the other brands.

Also from the brochure:

Mercury makes a direct comparison of their engine to a Yamaha:

Smooth Operator
Thanks to Mercury’s exclusive Focused Mount
System, the 115 FourStroke outboard produces
significantly lower vibration levels at the driver’s
seat throughout the rpm range than the 2014
Yamaha F115B – 50% lower at forward idle and
80% lower at the transom.

The brochure does not shy away from use of superlatives in describing this new 90-HP FOURSTROKE. On paper in this brochure, it sounds to me like the new Mercury 90-HP FOURSTROKE is the obvious choice. Are you willing to buy one?

jimh posted 05-29-2015 04:55 PM ET (US)     Profile for jimh  Send Email to jimh     
DONZI--is your MONTAUK boat one of the newer 170 MONTAUK models? Or is it one of the older, classic 17-footers. The year 2003 was a year when I believe you could still get both models.
Donzi posted 05-29-2015 05:04 PM ET (US)     Profile for Donzi  Send Email to Donzi     
Thanks Jim and other team members for your input! It's expensive to upgrade but well worth it.
Donzi posted 06-01-2015 10:24 AM ET (US)     Profile for Donzi  Send Email to Donzi     
After making a few calls over the weekend, I was not able to find a Mercury service dealer near Charlotte NC that could sell me a new Mercury and repower my Montauk. They said it is a separate franchise and they are rare in my area. I thought that was unusual. That does not appear to [the same as the marketing and sales arrangements between Yamaha and its dealers].

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