[Fr. Frank]

bushwhacker, thanks for the detailed explanation. sounds like im going back to the bigger prop w/ low cruise speed. i can just run it at 4500 instead. after all, id rather keep my bearings happy than save a few pennies at the gas pump. motor is at the right height by your description. thanks again guys, CSC never fails me.

Justin, if you're still running that Merc 200, you need to be turning between 5400-5800 rpms at wide open throttle. A lower max rpm will give you just the detonation and internal engine stress that Denny was warning you against. So when you cruise at a lower rpms, you're engine isn't straining so hard. It sounds to me like you still don't have the best prop, but finding the right prop is a process that always involves trial and error.

And just for the record, turning a higher rpm at cruise doesn't necessarily mean you're using more fuel.