Is this about right?

[benny429]

I should have written the speeds and rpm's down, but I think I remember it as:

4500 rpm approx 20mph
5000 rpm approx 22mph
5800 rpm approx 24-25mph

22 foot pontoon
23" logs
115hp Yamaha 4-stroke

I guess I thought full throttle would be a lot faster than a gas saving 4500 rpm or 4500 rpm would be a lot slower than full throttle.

[tkrein]

speed is all considered on variable weight water air temp. water temp things like that we just cannot go off rpm. same with your car if you go up a hill does your engine rev higher and use more gas to get you up that hill. if you are pulling a trailer doesnt it take more rpm to get you going and to mantain your speed same with a boat.more weight more the boat needs to push the toon up on aa socalled plain. if pulling a tuber you need more power.