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I recently repowered my 1989 Montauk with a 2007 Evinrude 90 HP E-Tec.
Love the engine. But one issue is the vibration. At varying RPM's I get a shake on the boat. I do not believe this is just the engine vibration being tranferred to hull. Has anyone heard of this or experienced this?

Philip
York Harbor, Maine

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I too, am interested in hearing reports of vibration of the 90 hp E-tec on an older 17' Montauk.

I was ready to repower with the 90 E-tec until I spoke with an Evinrude dealer in South Carolina. He said there is a vibration at certain rpm's that will make the side and bow rails rattle.

Anyone else hear of this vibration problem?

jb

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The 90 HP E-TEC is an in-line 3 cylinder engine.

Why does Jaguar and Mercedes use 12-cylinder engines on their expensive models? In general, more cylinders equals smoother operation (less vibration).

There is a rough spot on the 90 HP E-TEC. It is not enough to cause me to withdraw my overall endorsement of this motor as a repower option for Classic Boston Whaler boats. The weight-to-power benefits of this motor over most all 4-strokes far 'outweigh' the one point in the RPM range where there is a tad bit of vibration. You simply adjust your speed accordingly. This vibration, on my 2006 motors, occurs only at slow operation, however, I don't recall the exact RPM-point.

I would not hesitate to buy this motor again, given the opportunity.

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I powered my BW 17 outrage 1990 2 years ago. It's a great engine!!!
I've noted a light vibrtion at about 1000RPM. (but I think it depends on the boat shape also).
It's possible that you don't have the latest release of the software, in this case You have to upgrade it.
Renzo - Venezia Italia

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I tend to agree that more cylinders makes a smoother running engine.

However, I had a 1970's era 3 cylinder inline Johnson that had no abnormal vibrations. And more recently, a 2 cylinder 50 hp 1980's era Johnson that was very smooth running.

In a search, I found one owner of a 90 hp E-tec said the vibration from his engine lessened over time without doing anything.

Another owner said that switchng from a 17" diameter prop to a 15" one, lessened the vibrations.

Thank you for the responses.

jb

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Generally speaking, the even number of cylinders in an engine run with less vibration.

If I remember correctly, the 5 cylinder Audi engine had a counter balance on the crankshaft to basically act as a fake 6th cylinder. This smoothed out the vibrations of the odd number of cylinders.

Again, this is general as there are many smooth running, odd number of cylinder, engines.

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My 2004 E-TEC 90 had a slight vibration at 1200 RPM when I first got it. I swapped to a 15-inch stainless steel Stiletto prop, and let the engine settle in. It's all but gone. If you run it at Exactly 1200 RPM, there is a slight vibration. I run it at either 1100 or 1300 by sheer habit now, and it is unremarkable. It is unnoticeable during power-up. I am told that this is where the E-TEc's exhaust stratification mode engages, whatever that means...

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Oh, I friggin' wholeheartedly endorse this engine. 3 years later and it's runnin better than the day I got it.

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I don't know about where a lot of you guys boat,but i find myself in the 900-1400 range a LOT.Thanks to the Manatee zones down here in Fl.I have never had any issues with odd vibrations in my Mercury 3cyl carbed 90,i'd have to think this would be very annoying and probably harder on fuel.it's my opinion and only my personal belief,that if you spend that much money on a outboard,it should peform flawlessly throughout the entire rpm range.I personally wouldn't be happy spending a premium price and have anything less than premium performance.Again this is just my opinion.I'd try to get a leftover BRP V4 carbed 2 stroke or a mercury carbed 90 classic 2 stroke if i were in the market for a 90 hp outboard.

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I hear what you are saying Bob. I will be making a new outboard decision in the next year. More than likely a 90HP motor. My wife has been adamant about buying a 4 stroke to help the environment. Problem with that in my application will be weight. I showed her the "powerful choice" dvd from Evinrude and now shes hooked. (power of marketing I know) If you need a lightweight 90HP thats environmentally friendly you have about 3 choices. Optimax, ETEC or TLDI. Of those choices I think ETEC is probably the best of the bunch.

What do you think?

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I totally agree that your limited in the "enviro friendly" division,and i can't see how the Opti is even in the running in this 90hp class.Those things(merc opti's) are just too darn heavy for a 90hp IMO.I'm just too much of a cheapskate to pony up extra cash to have a cleaner outboard i guess.As for that TLDI,if it's been anything like my 2004 Nissan 40hp,i'd pass on it.I have 20 hours on mine and it's going to the shop for the 8th time to have the carbs looked at.Runs awesome when the carbs are right,unfortunately they don't seem to want to stay that way.Might drive a little further to a new dealer and see if that fixes the problem.

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Its a really tough decision when you are spending that kind of money on an item that will do nothing but depreciate in value. Did you see the new 90 Mercury FourStroke - I just saw it at the AC show- This thing is huge!
[IMG]http://img.photobucket.com/albums/v472/sraab928/S6000024.jpg[/IMG]

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The only boat I own I would even conteplate dropping a 4 stroke on is my 21 Revenge and only because that hull can handle a lot of weight on the back with no problem.I am a firm believer in the K.I.S.S(keep it simple stupid) rule.I don't like high tech wizardry and especially in a marine enviroment with all it's corrosion problems to contend with.However it looks like the manufacturers are getting the bugs worked out with the reliability problems.the only thing that still puts me off about the DFi motors is they seem to be a tad weaker compared to thier old dirty carbed ancestors(mostly just on the top end to be fair) and i am a skin flint.So if i pay $2500 more for a 90 hp DFI than a carbed 90 2 stroke,that darn thing better out perform that old 90 on every level,not just a couple.Thats just my feelings on it.I looked into the Etecs when i was in the market for a 90 and they were about $2500 more and from what i have heard and seen first hand,they seemed a little on the weak side.Now becasue that boat is mainly a toy,that was a big concern of mine,not fuel economy,emmissions,noise(although my 90 is whisper quiet to me) and cost.
Etecs seem to be good repower options for our Whalers,but there's other offerings in the DFI market that seem to fit the bill as well.Shop wisely and figure out what exactly is most important to you.

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I will definitely shop wisely.

Is there much difference between your 2005 Mercury and my 2001 Mercury? I like my Mercury's performance overall but its a bit noisey and puts off some smoke. Not much but some. How has yours been treating you? Any reason you picked the Mercury 2 stroke over the Yamaha?

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It's funny you say it's noisy,i think the darn thing is too quiet myself lol The only difference is i have the 2.3-1 lower ratio and you have the 2.0-1 ratio.other than that they are the same as far as i know.The 90 Yamahas seem a bit weaker than the Merc 90's,however they do have aftermarket support for upgrades.I know it's no true test,but i ran a guy in a 15 Key west with a 90 yammy on a jackplate and he had it cranked pretty high.he was about 200 lbs and his wife was around 110 or so.I was in my 15 Mischief with the motor bolted right to the transom as high as it will go,no jackplate and had my 220 lb butt in it with my 350 lb buddy and i still walked the dog on the guy from a standing start through the top end.i am pretty sure that Key west is a much lighter boat too.
I haven't really looked into the Nissan TLDI's,dealer network would be a issue with them.

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I think a big part of making the outboard decision is available dealer support. The best dealer in my area only carries Evinrude. Their service is spectacular. Other than that we have a bunch of dealers but all in all they are ok.

I have been happy with my 90 Mercury overall. Of course it did break down on me at the end of the season. Turned out to be a bad stator. I was able to fix it myself which saved me some money and I learned a bit in the process too. Maybe I will just hang onto the Merc for now. I am so confused ;)

By the by, love this site. Great edit function, image posting, smileys :D. I hope it really starts to catch on the traffic increases.