Achieving WOT RPM's

[Hareball29]

I have a 24' pontoon with a 90hp Nissan OB. Book says WOT RPM is 5000-5500, I can only get 3000 rpm with half full (or empty) fuel tank (29 gal) and three people on board. I have replaced the prop with a 15 pitch, 3 blade and have decarbed the engine. Still no luck. Was mentioned that throttle cable may need adjustment, any suggestions?

 

[MajBach]

Re: Achieving WOT RPM's

toughie. Does it 'sound' like more than 3000? It's either your tach or to coarse a pitch.

 

[TOHATSU GURU]

Re: Achieving WOT RPM's

It can be anything from the pontoons being filled with water to having a blown cylinder on the engine. What was the pitch of the other prop and what was it's RPM at WOT?

 

[Hareball29]

Re: Achieving WOT RPM's

I just bought the boat but had compression checked before putting in water. Pitch matched up with old prop. Not sure about the water in pontoon.