Yamaha 4 stroke 150 HP

[JeffCharger]

I am and faithful 2-stoke guy, but am looking at a family ski boat and considering a Yamaha 4 stroke 150 HP versus a 2 stroke version. I need some help. I am primarily interested in understanding the performance comparison of these two motors. So, specific questions include:
- how do they compare out of the hole?
- how about top end?
- fuel economy at cruising, top end and slow speeds?

Any other disadvantages/drawbacks?

Any insight would be helpful. (reliability, maintenance, etc.)

Thanks

[sosmerc]

You can go to Yamaha's website and review their performance bulletins. Find similar hulls tested with different models...2 stroke vs. 4 stroke and you should be able to draw some valuable conclusions.
I have not run the 150 4 stroke Yamaha, but I have run the Yamaha 115 4 stroke vs. Merc's Optimax 2 stroke 115. The 2 stroke was much quicker out of the hole and faster on the top end. I didn't compare fuel economy, but I'm sure they are pretty close.
I'm sure the 150 Yamaha 4 stroke is a fine engine, I'm just not sure you'll be happy with it as a ski motor compared to what you might be used to.
Cost of maintenance should be pretty equal, although over the life of the engine the 4 stroke may prove cheaper in that I believe the 4 strokes will live longer in terms of hours of service. But when the 4 stroke is dead it will probably cost too much to rebuild...you just buy another one when the time comes. :D

[VectorPat]

The Yamaha F150 is the most popular motor they have right now. Check the weight on it ,very close to the HPDI..And unlike many other 4strokes it makes an honest 150hp..

[baja200merk]

i watched a yammi F225 push a big 20ft sun deck type boat to 50mph spinning 6200rpm (too little pitch) but its a 225..

the only thing about the 4 strokes people like is the fact that you dont have to look at the engine to see if its pumping water you can hear it pissing out over the engine noise..

i think 4 stroke sucks! NO NOISE? NO SMOKE? WTF KIND OF OUTBOARD IS THAT!?!?!:p

KEVIN;)

[DoktorC]

We've got an F150 on our 17' Lund fisherman (windshield, top..fairly heavy). It pushes it to 58mph on the GPS which isn't bad for that hull. The F150 actually makes alittle better than 150hp. It's much small looking then the V6 hpdi (which I have), its quieter, and waaayyy better on gas at cruising speeds. In short I don't see a down side to the motor other then the image...it doesn't look all that cool. But, from what I hear, up here in Canada we're getting some limited edition VMAX F150's. This will just be a graphics package but it'll look way better.

[sosmerc]

DoktorC.....
on your 150 four stroke, when does the owners manual call for a valve adjustment?

[DoktorC]

That I don't know. I can look but it won't be untill the weekend. If it's like my sled it'll be 35000 kms :).

[mercmack]

ITS A POSSIBILITY THAT THE REST OF THE MERC VERADO FAMILY OF ENGS WILL BE OUT LATER THIS YEAR, AND I AM SURE THEY WILL HAVE A 4 STROKE 150 AND MOST LIKELY WILL BE EITHER A 4 CYL OR POSSIBLITY A 5 CYL MODEL. AND IF IT HAS THE SUPERCHARGER LIKE THE BIG ONES, IT SHOULD BE A LOT BETTER AT THE BOTTOM FOR SKIING...JUST A THOUGHT:D :D :D

[DoktorC]

or..you could just go ahead and buy 2 f150's...one outboard and one truck for the price of a Verado..rigging..and the new Mercury boat that it comes with so it'll work right :).

[sosmerc]

No doubt Merc will be releasing smaller versions of the Verado, but I'd be surprised if we see them this year....my guess is, maybe middle of next year.
And, no doubt they will be pretty impressive, if they are as feature packed as the new Verados.
They won't be cheap, but then, what is anymore? They will be competitively priced with the rest of the market.
I'm still kinda hoping that Merc will build some small Optimax models. I've run the new 115 Merc Optimax and I really liked it.
Heck, a 4 cylinder Optimax producing 125 to 135 might be a winner also. Simpler and lighter than a V-6. Yea, they should do that.:D

[Markus]

Does anyone have experience with the 90 hp Mercury 4-stroke built by Yamaha? How does it compare to the 90 hp 2-strokes?

I am going to help a friend look at used boat that is rigged with one.

[RRRevinrude]

only down side to the 90 is that its carbuerated....very small jets that clog up easily if they sit for any legnth of time...115 and up are fuel injected and lots easier to maintain....the f150s run very close to the 150 2 strokes power wise and weight is very close also....probably the best 2-4 stroke matchup out there.....the smaller 4 strokes don't match up power or weight wise...the big ones have plenty of torque but weight becomes a factor on small boats.......................greg

[Markus]

RRRevinrude, thanks for the info.

[Backfire]

In the 90 class, better look at Evinrude E-TEC 90. If the wait isn't too long because they are on back order,selling faster than they can make them. Extremely quite, extremely fuel efficient, no smoke,less emmissions, weighs less, strong performance---why a 4 stroke?
Backfire ;)

[sosmerc]

....not to mention that Merc and Bomb can make these DFI 2 strokes run on just about anything if they want to. I wish Etech success....just so Merc will see the light and make some more Optimax models!

[Markus]

There is no risk that I will run a 4-stroke in the forseeable future.

But a friend is buying his first boat, and the model he is looking at is made by one of Brunswick's boat companies (they even have one in Sweden), so pretty much every used boat out there was pre-rigged with a Mercury.

Since the boat is rated for 135 hp, I am trying to talk him into finding one with a V6, but it seems like most of them were sold with 90 hp Mercury 2-strokes or 4-strokes.

If it were a new engine, the eTec would definitely be the way to go if it had to be a green 90 hp engine. I would still prefer a 90 hp carburated 2-stroke Yamaha or Tohatsu (if they still make them) , though.

[JeffCharger]

thanks for the help guys. I appreciate it. ....