yamaha motor

:?: O.K. Here is the question that I have...I have a yamaha 28 jet, 1998, and this is a 40 hp. power head. The 40 and 50 share the same specs,same motor but some thing different. What is the differance and can I make the changes myself. This has been bugging me for a whole. I just can not put my finger on it.

This question gets asked a lot on a couple motor repair forums I am on. Short answer, no, it usually isn't practical.

Long answer. Yes, it can be done. The biggest question is usually with converting 9.9 to 15. For a bit, certain OMC 9.9s were detuned 15s, and once someone figured that out, everyone wants to do it to any ole' outboard.

But, on most motors, it isn't cost effective. Often, the powerhead may have the same bore and stroke, but that could be the end of all similarities. Now, I am not at all familiar with Yammies (nor do I see a need to become familiar with them any time soon :wink: ) but I think I know where you could get the info on the practicality of doing this. Check your PMs. But, the chances are, you will be better off trading up to a larger motor.

Thanks bassboy1. For now I will just live with it and not be in such a hurry!!

Sometimes, it as easy as changing the carbuerator to one that flows a higher cfm.

jetdrive1 said:

Thanks bassboy1. For now I will just live with it and not be in such a hurry!!

Click to expand...

Did you get my PM? My inbox still lists it as unread.