Yamaha 40hp slipping.

[Clarky]

I have a 2000 Yamaha 40hp 2 stroke on my pontoon boat. It was working fine last year until I went to take it out for the season. Then, everytime I would give it some throttle, it would rev up, but the boat would slow down. It was like a clutch slipping, or something.

I just put it in this year for the first time. I changed to a different prop. It did the same thing. People have told me that the hub probably is slipping, but I have tried 2 different props. I have never hit anything with either prop.

I don't know a thing about outboard motors, but I am pretty sure there is no clutch in them that would be slipping.

Does anyone have any ideas why my motor would appear to be slipping at mid to full throttle?

Thanks in advance.

John

 

[Ray Neudecker]

Re: Yamaha 40hp slipping.

Normally a hub will slip when trying to plane off which is the greatest time of stress on it. Some times a fuel restriction will often give the same impression. If it is accompanied by a surge if you have it wide open, you then have a fuel restriction.