Mercruiser 3.0L on Glastron SE175 prop

[bjromaine]

I have a 1998 Glastron SE175 with Mercruiser 3.0L and Alpha Gen II outdrive. The boat has just had a tune up including bellows replacements. When running with 3 people on the boat, it developed about 5200 RPM (per boat tach) at about 41 MPH (boat and GPS speed). Is a 19 pitch prop too small? The WOT is supposed to be about 4800. It has power trim so upping the prop pitch shouldn't have a negative effect on the holeshot, correct? should I expect more speed from this boat and motor combination?

 

[Chris1956]

Gee, I think the boat speed is pretty good for that engine/boat. Using a prop with more pitch will slow your hole shot, but it might increase your top speed. There won't be much difference, I wouldn't think. A 21P prop should (in theory), lower your max RPM to 4800. Depending on the type of prop, you may get a bit better bite on the water, can trim a bit more and increase the top speed a couple of MPH.