Moderated Discussion Areas
  ContinuousWave: Whaler Performance
  90-HP Yamaha: 2-stroke vs 4-stroke?

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   90-HP Yamaha: 2-stroke vs 4-stroke?
NausetBoy posted 04-16-2003 07:22 PM ET (US)   Profile for NausetBoy   Send Email to NausetBoy  
Repowering my Nauset. I have been a Yamaha user since the 70s and Im set on em. What are the pros and cons [of 2-stroke vs 4-stroke]? Are there any known problems with either engine? thanks a million!
JBCornwell posted 04-16-2003 08:12 PM ET (US)     Profile for JBCornwell  Send Email to JBCornwell     
Ahoy, NausetBoy.

Not an expert, but here are some notes from my own search for repower a couple of years ago:

Yamaha 90 2S: light weight, very good reputation. Seemed short on torque in demo. Probably because it is highly stressed to make 90HP with only 70ci.

Yamaha 100 4S (this engine is now rated at 90HP): Pretty heavy at over 350lb. Smooth as warm honey. Quiet, too. Plenty of torque. Too bad it is carbed. I want EFI in a 4S for the computer management, if nothing else.

OMC 90s. Great torque and top end. The Evinrude is too heavy. Both were in limbo as to warranty. QC problems.

I ended up with a Suzi DF70 EFI 4 stroke and love it. My decision was highly influenced by another Montauk owner who had a Mercury 90 4 stroke and convoyed with a bunch of Montauks with Suzuki's and Evenrude's (rebadged Suzuki's] . He wished he had one instead of the Mercury.

If you are determined to have a Yamaha, I recommend the 4 stroke carbed F90.

Red sky at night.. .

whalernut posted 04-16-2003 09:14 PM ET (US)     Profile for whalernut  Send Email to whalernut     
JB, how much does the Suzuki 70-HP 4-stroke weigh? Thanks-Jack.
JBCornwell posted 04-16-2003 11:14 PM ET (US)     Profile for JBCornwell  Send Email to JBCornwell     
Hi, Whalernut.

There are two different published weights.

Mine weighs 336lb, but later Johnson literature states it at 356lb.

I have no explanation for the difference.

Red sky at night. . .

jstachowiak posted 04-17-2003 12:11 PM ET (US)     Profile for jstachowiak  Send Email to jstachowiak     
I have a 2001 Evinrude (rebaged Suzuki) 70-HP on my 1979 Newport and the weight sinks the rear so the two splashwell drain holes are under water or about 1 1/2" more than the 300 lb 90-HP Mercury that was on it prior.

Other than that the boat planes and handles just like the 90HP 1979 Mercury I had on it prior.

I agree that this is the best motor available today for this boat.

Top end speed is 37 mph at 5600RPM running 13 1/4" x 17 pitch OMC SS prop.

tbyrne posted 04-17-2003 01:17 PM ET (US)     Profile for tbyrne    
I have the Yamaha 80 (now marketed at 75 hp)and love it (as JB says: "smooth, quiet, torquey" - I'll add "efficient"), although it is fairly heavy. It does not seem to really be an issue on my boat (an 18' Rothbilt [1,400 lbs.), but it might be on an 850 lb. Montauk.

The Suzuki seems to be a bit lighter although the weights of all these motors seem to be "restated" by the mfrs each year. (My Yamaha 80 was originally billed as 356, but now is billed as 370 or so. As Bigshot said, the Su[author's pet name for engine] was billed at 335, but Johnson now says more. Who knows?)

Have you considered dealer support? The Suzuki dealer at which I would have bought a 70 has since disappeared (East Coast Outboard in Old Saybrook, CT), so I am glad I chose the Yamaha.

What about the Mercury 60? Does its lighter weight make sense for you?

If you need speed and are set on Yamaha, buy the 90 Yamaha 4-stroke and put the battery in the console to lessen stern weight or just get the Yamaha 90 hp 2-stroke, which is probably the lightest 90 out there (although not as strong as the OMC 90 2-Stroke).

flawton posted 04-17-2003 04:30 PM ET (US)     Profile for flawton  Send Email to flawton     
I have 10.5 hours on my Yamaha 90 2-stroke that was installed on my 1981 NEWPORT approximately 6 weeks ago. I really like it and it pushes the boat nicely. I went with the 90 2s for the following reasons.

1) weight, 262 lbs. the boat sits very nicely in the water and I could put a 100lb cooler in the stern without it being too stern heavy.

2) tried and true. From what I have read about this engine and have talked to owners of the 90 2s, they are bulletproof. I have heard some on this forum say "antiquated" when refering to the 90 2s to which my reply is "if it ain't broke don't fix it".

3) Price. Im a believer of putting as close to the max hp on a boat as you can for better performance (espicially under load). When I was pricing the 90 2s and the 100 4s (now the 90 4s), I was finding that the 4s was $1,000 to $1,500 more.

4) I like the smell of a 2s. I grew up with them and it reminds me of my childhood on the water when I smell that intitial puff of smoke.

If you are comfortable with the 360 lbs. on the 90 4s get the 115 hp 2s (also 360 lbs.), you will get the 25 extra hp and will have a ball with it.

Whalebones posted 04-18-2003 08:57 PM ET (US)     Profile for Whalebones  Send Email to Whalebones     
I have 79' Montauk (weighs about 900lbs.) that I need to repower. I'm in Calif. so the 4 stroke seems to be the trend with EPA laws as they are. My friend has a 4 stroke 90 Honda on his Montauk and likes the engine but in my view it's too heavy, 375lbs, he has plugged the hole in the engine well to keep out the water. The ocean is where I do all my boating. I like the idea of the 244 lb. fuel injected 60 HP Mercury 4-stroke. If I can cruise comfortably at 26 to 30 mph it is ok with me.
I looked a brand new Montauk (weighs about 1400 lbs.)today at the dealers and it has been designed for these heavy 4's the dealer said (max. 410lbs. min. 60HP Mfgs engine window)
Has anyone tried this set-up, 60hp 4s Merc. on an older 17 Montauk?
The Merc. 60 HP is the only fuel injected model 4s at that HP rating from what I can find. (By the way I'm replacing the original 70HP 1979 Merc.)
Coments, thanks
Perry posted 04-18-2003 09:58 PM ET (US)     Profile for Perry  Send Email to Perry     
Bones, you might have better luck with responses if you start a new thread and address your situation.

[At this point, I edited the thread and changed about a dozen or so occurances of "pet names" like Zuki to say "author's pet name for engine". This had an impact of making the thread hard to follow, since you could not tell what engine was being discussed. That prompted the following comments.]

jimh posted 04-19-2003 12:28 AM ET (US)     Profile for jimh  Send Email to jimh     
Pet names for engines are strongly discouraged.
andygere posted 04-19-2003 12:42 AM ET (US)     Profile for andygere  Send Email to andygere     
Jimh, you made me laugh. I think folks should get the point.
Perry posted 04-19-2003 01:20 PM ET (US)     Profile for Perry  Send Email to Perry     
Yea, whats up with the Zuki, Yami, Johnny, JhonnyRude, JohnnyZuki, Mercyami stuff it sounds raher silly to call outboard motors these pet names.
JBCornwell posted 04-19-2003 02:20 PM ET (US)     Profile for JBCornwell  Send Email to JBCornwell     
It sounds rather silly to me to object.

Red sky at night. . .

Perry posted 04-19-2003 04:23 PM ET (US)     Profile for Perry  Send Email to Perry     
I don't object to using pet names for outboard motor brands, I just think it is silly. Jim brings up a good point that it makes it easier for someone to find info on a particular brand of outboard using the site search when it is referred to as its proper name.
Eric posted 04-19-2003 05:56 PM ET (US)     Profile for Eric  Send Email to Eric     
I was getting really annoyed trying to figure out what brand these threads were about. Now that I see what Jimh was doing: trying to make it possible for a search to be done to locate this thread later.

Since this is one of the most common topics, I think that I'm converted: Jim I see your point.

John O posted 04-19-2003 06:56 PM ET (US)     Profile for John O    
So if one needs to research info on "author's pet name" one will be very happy.


JBCornwell posted 04-19-2003 07:49 PM ET (US)     Profile for JBCornwell  Send Email to JBCornwell     
I see your point, James. I hadn't thought of making the info and comments available for a search.

On the other hand, use of the insulting, "silly" is an excellent example of how members are unnecessarily offended and driven away from this site.

Nicknames (or is it Nicholas names?) are very commonly used throughout the web and the industry. It might be more accurate to refer to them as "service industry pet names".

Red sky at night.. .

hooter posted 04-19-2003 08:01 PM ET (US)     Profile for hooter    
Mebbe Ah'm a doofus, but Ah've still not figured what you fellers are talkin' about. Could somebody talk plain English for just one friggin' post, here?
lhg posted 04-19-2003 08:07 PM ET (US)     Profile for lhg    
I agree with JimH, having previously been an offender with "Merc", although Mercury does use this logo on their 300HP 2-stroke EFI engine.

I think "Yami", "Yammy", "Suzi", and "Zuki" would be great names for the family cat. Believe it our not, an ex-ladyfriend actually had a cat named "Zuke". And "Johnny", "Rude" and "Merc" could be given the family pooch. Honda and Tohatsu seem, so far, seem to have escaped the pet's name lingo.

whalernut posted 04-19-2003 08:24 PM ET (US)     Profile for whalernut  Send Email to whalernut     
Hello, my name is John-Pet name is: Jack. I think the pet names are cool, it really isn`t a big deal, except for the search thing, but I have never used it :) Jack.
Perry posted 04-19-2003 10:37 PM ET (US)     Profile for Perry  Send Email to Perry     
JB, I think it is silly to use a pet name when refering to your outboard motor. Others agree and some even say they are annoyed by it. If you are offended by me stating my opinion, I'm sorry. It wasn't meant to be offensive and I hope I haven't driven you away from this site because of my remark.
JBCornwell posted 04-19-2003 11:16 PM ET (US)     Profile for JBCornwell  Send Email to JBCornwell     
Perry, I have never used MY pet name for any engine.

I have used very common short names for many brands of engines, just as I often refer to Chevys, Caddys, Beemers, HemiCudas, etc.

If you find engine enthusiasts' terminology silly, the gentlemanly thing to do is not mention it, rather than risk a counterstroke of similarly derogatory adjectives from those who find them fitting comment on your opinion.

Red sky at night. . .

JBCornwell posted 04-20-2003 07:26 AM ET (US)     Profile for JBCornwell  Send Email to JBCornwell     
Peace, Perry.

I am overly sensitive to comments that seem to ridicule harmless ideas.

Red sky at night. . .

flawton posted 04-20-2003 10:39 AM ET (US)     Profile for flawton  Send Email to flawton     
Yami, Yammy, Yammie - silly, silly, silly

Political correctness - BLAH BLAH BLAH

whalernut posted 04-20-2003 10:49 AM ET (US)     Profile for whalernut  Send Email to whalernut     
Political Correctness Sucks and shouldn`t exist :( Jack.
jimh posted 04-20-2003 04:33 PM ET (US)     Profile for jimh  Send Email to jimh     
My comments have nothing in the world to do with political correctness. They are based on a much more practical reason: being able to locate articles in the search engine.

If I want to read about Yamaha engines, I ought to be able to type "YAMAHA" into the search engine and let it find the articles. With all the silly spellings in use you'd have to search on:

and so on.

And in a similar fashion, you'd have to search for information on Evinrude under

Evenrude (misspelling)

and so on.

If I want to find out about the RAGE model, I really don't need to get responses where someone decided it was cool to call his OUTRAGE a 'RAGE.

What is the big deal about using the real name of the company?

It is a good thing we don't have more Canadian authors. People in Canada seem obsessed with shorting the names of things. I notice that they don't have Chevrolet dealers, or even Chevy dealers, but they have Chev dealers.

When you order at Tim Horton's you don't ask for an "iced cappuccino" you ask for an "ice cap."

I was just having some fun with this post, anyways, I'll put all the engine names back in so people can get some information from it again.

Perry posted 04-20-2003 04:51 PM ET (US)     Profile for Perry  Send Email to Perry     
JB, you made a good point. In the future I will be more careful in my word selection so as not to offend anyone on this great forum.
Peace and Aloha,
jimh posted 04-20-2003 04:53 PM ET (US)     Profile for jimh  Send Email to jimh     
[Administrative post]
flawton posted 04-20-2003 08:41 PM ET (US)     Profile for flawton  Send Email to flawton     
jimh, I agree with you boss, relax.

NausetBoy posted 04-22-2003 04:36 PM ET (US)     Profile for NausetBoy  Send Email to NausetBoy     
Any answers? The topic aint outboard pet names!
JBCornwell posted 04-22-2003 05:48 PM ET (US)     Profile for JBCornwell  Send Email to JBCornwell     
Four stroke, Nauset Boy.

I thought I said that.

Red sky at night. . .

Mark D posted 04-24-2003 07:06 AM ET (US)     Profile for Mark D    
I repowered my 17' Montauk from a 70 Evinrude 3 cylinder to a C-90 Yamaha 3 Cylinder. It was a direct bolt up to the old holes on the transom from the OMC. Same weight as the 70 but more horses more torque. (Its basicly the same design just better.) Performance is great; nice hole shot with two 190 lb + adults with 26 gallons of fuel. 35 mph (gps) @ 5100 + or - rpm. Stainless prop too.
A friend of mine has a newer 90 OMC 4 cylinder. Very smooth running nice engine.
whalernut posted 04-25-2003 05:42 PM ET (US)     Profile for whalernut  Send Email to whalernut     
Mark, those 70 and 90 h.p. Yamaha C-series engines have caught my eye, they are the last larger Mix engines left, but I could be wrong, I love the simplicity of the non-oil injected models, but sadly I imagine Yamaha will delete them from their line up in the future, EPA emissions and all :( Jack.
whalernut posted 04-25-2003 10:35 PM ET (US)     Profile for whalernut  Send Email to whalernut     
I just checked the Yamaha and just what I feared the C-Series is history :( I would summize that it was lack of sales or the writing was on the wall with the low emmisions laws, I would think the 2nd theory is the one, man can`t we keep just a couple of these around for us dinosours :) Jack.

Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.