RPM help

[ando]

I have a 50 hp yamaha 2 stroke (2003) on a 20 foot pontoon boat . I believe the spec for this motor is 4500 to 5500 wot rpm. The wot for this outfit is 4800 . The boat runs fine and handles well . Will 4800 wot rpm cause motor issues in the long run ?

 

[pine island fred]

Re: RPM help

I would not be happy with that. Others might disagree but I think you are overpitched on the prop. The next size up is a 70 and the operating range is 5K to 6k. I would look for something close to 6K RPM. Compression ration on that motor is 6 to one which tells me they are wary of detonation ( caused by HI manifold pressure ). My 49 CHEVY did better than that. FRED