what is the difference in 90 and 115

[jmidkiff]

want to convert 2003 90 2 stroke to 115 can it be done

 

[noelm]

Re: what is the difference in 90 and 115

If you are talking Yamaha, then you will need to convert a 3 cyl inline to a V4, be a pretty big job I would think!

 

[jmidkiff]

Re: what is the difference in 90 and 115

can you just boost hp of the three cylinder and how

 

[noelm]

Re: what is the difference in 90 and 115

I guess there maybe some ways to wring a bit more HP out of that engine, but it is a fairly small capacity motor pushing out quite a bit of HP for it's size now, I would think if it could be reliably done, Yamaha would have done it long ago, and had the lightest 100HP outboard on the market by a long shot! leave it as is and/or trade in on a 115HP.

 

[Silvertip]

Re: what is the difference in 90 and 115

Look at it this way -- if Yamaha could have wrung 115 HP out of the three banger, they would have done so rather than have a 115 V4. Now if you would have asked could a 115 V4 be converted to the HP rating of other engines in the V4 block the answer is probably "yes - but". The "but" part is how much money do you have. These changes are easy for the factory to do but very expensive for the consumer.

 

[robert graham]

Re: what is the difference in 90 and 115

The Yamaha 90HP 2 stroke has 70 cubic inches of displacement producing 90HP, which is about 1.3HP per cubic inch, which is a fairly high state of tune. I have no doubt that Yamaha or a darn good 2 stroke mechanic/engineer could squeeze 115HP from that block, but the engine would give up a lot in terms of tractability, dependability and efficiency. The modern outboards, like modern automobiles, don't lend themselves to very well to shade-tree hot-rodding. Good Luck!