90 2 Stroke vs 115 4 Stroke...

Oakgrove Boater · May 24, 2002

I am purchasing a 17' Keywest CC and am undecided about which Yamaha motor makes more sense. The 90 two stroke carbed or the 115 four stroke with fuel injection. Performance and reliabilty mean more than cost(about $2000 diff). Any thoughts?

manitoba1 · May 24, 2002

Re: 90 2 Stroke vs 115 4 Stroke...

If cost is not a consideration then your answer is very easy. The fuel injected four-stroke 115 will not only be quiter and more fuel efficient but will have more power, idle and troll better and won't pollute like the 2 stroke. I went from a Suzuki 55hp 2 stroke (which was a good engine) to a 70hp digital fuel injected four stroke Suzuki and the difference is amazing. The 4 stroke has significantly better performance, better fuel economy, and is the smoothest quitest engine I've ever owned or operated. With a fuel injected engine you just turn the key and it starts always without any choke. Enjoy your new 4 stroke.

JB · May 24, 2002

Re: 90 2 Stroke vs 115 4 Stroke...

I agree with Manitoba, provided your Key West is rated for 115hp and can handle over 400lb on the transom. If not, consider the Johnny-Uki DF70 EFI 4 stroke. I have one on my 17 Boston Whaler and my experience is the same as Manitoba's. The smoothest, quietest engine ever. Good luck.

my new fishmaster · May 24, 2002

Re: 90 2 Stroke vs 115 4 Stroke...

The 4 stroke Honda would be the way to go. If you are going to spend that money get the best/resale engine. The 90-115 Would work fine

JB · May 24, 2002

Re: 90 2 Stroke vs 115 4 Stroke...

The Honda 90 is carbureted and weighs 378lb. The Honda 115 is EFI, but weighs over 500. This man is looking at a 17 foot boat that shouldn't have over 350 on the transom. Hondas are nice engines when used where they are suitable. They are not superior to other 4 strokes in their class, and in several cases are obsolete by comparison.

Oakgrove Boater · May 24, 2002

Re: 90 2 Stroke vs 115 4 Stroke...

I appreciate all the help guys. As stated too much weight will kill the self bail feature so we are planning to move the battery up to the console. My dealer nixed the Honda idea because of the weight. I would rather have the Merc 115 but my dealer says they are impossible to get. Seems as though Yamaha makes Mercs powerhead on the 115 4 Stroke FI and Yamahas are selling fast enough they are holding out on deliveries to Merc. Will the 115 4s preform as well as the 90 2 stroke with accel and/or top end?

mnmfors · May 24, 2002

Re: 90 2 Stroke vs 115 4 Stroke...

I know a guy that had a merc 225, and swapped it with a 225 yamaha. He is happy with the change, but the get up and go, got up and left his boat. Fuel economy is way better, and is very quiet. It is quite slow getting up on a plane with full fuel tanks and 4 people. We are experimenting with diff. props, and it is helping. (WOT is at 5900) We are sure it is the weight causing the accelleration difference.

Frank Martin · May 24, 2002

Re: 90 2 Stroke vs 115 4 Stroke...

Please its hard to to argue with the peolpe that have the honda motors they wouldnt own anything else myself included been a johnson and evienrude loyalist for years. For many years weight was a issue your facts on weight are corect but the reason honda peolpe beat their drum is because of there personel experience with the product. Its unbelievable reliablity is best exhibited in Hondas lines of Cars, lawn mowere, and generators. These are the same engines Honda puts in their outboards. Ask anyone who onws anything with a Honda engine in it, once you own a Honda you will be hooked for life by their great quality engines. Yes, they might cost more then other engines but you are paying for what you get. The lightest and BEST 4-Stroke engine on the market. Frank

RJS · May 24, 2002

Re: 90 2 Stroke vs 115 4 Stroke...

In this HP range, I would go for the 4-stroke and definately fuel injection. Trust me, you will be extremely happy with fuel injecion vs. carburation. Analogy: does anyone have trouble starting their later model cars in winter (even American cars); ie., since fuel injection ?

mnmfors · May 24, 2002

Re: 90 2 Stroke vs 115 4 Stroke...

I guess it is more of a question of the use of the motor. If you like fuel efficiency, nice quiet motors, etc., 4 stroke is the way. Me....well....I like speed....love to hear the motor....and dont care about the fuel milage...the difference between 2-stroke and 4-stroke in a large hp motors seem to be about $3-4k. That is a lot of gas! Honda would be my first choice on any generator, I was told they lead the way in their car engines (most hp). Heck I probably would never be able to afford a brand new motor, I just keep patching together my old merc. 2 stroke.

Oakgrove Boater · May 25, 2002

Re: 90 2 Stroke vs 115 4 Stroke...

The boat is rated for 120 HP I wonder if it will feel natural not breathing burned oil if we ski?

DJ · May 25, 2002

Re: 90 2 Stroke vs 115 4 Stroke...

TI, Nope it won't. I can recognize that smell anywhere. Here's an idea, buy the 2 stroke and send the $2G to me.

lakensea · May 25, 2002

Re: 90 2 Stroke vs 115 4 Stroke...

We normally rig the 17' Key West with the Suzuki DF70, but we have installed DF115's. The weight is 416lbs and we replace the stock flap scuppers with the ball type.

evin300 · May 25, 2002

Re: 90 2 Stroke vs 115 4 Stroke...

mmmm..... no mention of DFI in here?

Chrishath · May 26, 2002

Re: 90 2 Stroke vs 115 4 Stroke...

Mike It's not just the greater weight of the 4 stroke that's giving you trouble w/ acceleration: powerband and torque differ greatly between the 2 strokes and 4 strokes of the same hp. Even if the 4 was lighter, you would still plane faster w/ the 2

90 2 Stroke vs 115 4 Stroke...

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