Hello,
I have an 18' Voyager pontoon boat with a Yamaha 40 hp 4 stroke. I have a Yamaha 11 5/8 D by 11" pitch prop. Using a Yamaha marine mechanics tach (which agrees with mine) I can get only 4700 rpms at WOT. The mechanic has verified all is running well and compression, fuel pressure and timing is fine. It starts easily and smooth idles at about 900 rpm. 5000-6000 rpm is supposed to be WOT limits. Any suggestions or comments would be appreciated. Is 4700 rpm close enough? I don't want to go stainless.
I have an 18' Voyager pontoon boat with a Yamaha 40 hp 4 stroke. I have a Yamaha 11 5/8 D by 11" pitch prop. Using a Yamaha marine mechanics tach (which agrees with mine) I can get only 4700 rpms at WOT. The mechanic has verified all is running well and compression, fuel pressure and timing is fine. It starts easily and smooth idles at about 900 rpm. 5000-6000 rpm is supposed to be WOT limits. Any suggestions or comments would be appreciated. Is 4700 rpm close enough? I don't want to go stainless.