Over Prop

[ColdDuckCapt]

Could my boat be over propped?

I own a 30ft SeaRay for the past two years. Ever since I bought her, the engines have strained at 3100rpm and eventually gets out of the water. The bottom is clean, tabbed correctly and outdrives full-down.

Could the pitch of my props be to blame? Not allowing a high enough RPM?

Thanks

[Inthewind]

Yes, it sounds like you could be overwheeled. Once your up on plane, what are the highest rpm's that you can achieve? You should be able to wind up the engines to around 4500 to 5000 rpm's if you have twin 350 chevy's. Cruising rpm's on the high end would be around 4100 rpm's. Actually a twin engine 30 foot searay should be able to get up on plane seemingly effortlessly. Are they healthy engines, if so, I would say your overwheeled.

[David M]

I agree, if the engines are healthy and the engines cannot reach their maximum rated RPM, then you are over propped. Many engine manufacturers will not honor their warranty on an engine that is over propped.

What happens is the engine is never able to reach its maximum horsepower at lower RPM's, therefore you never reach the boats maximum potential speed.