prop suggestions

[klw]

I am sure this question has been asked before but here is my problem. My boat is a Stratos 375 with a 115 Yamaha 4 stroke. The problem is that at wide open throttle I am only able to get about 4800-4900 RPM. WOT is rated at 5500-6000 RPM for this motor. I currently have a 13.5 by 18 prop. What way do I need to go with the pitch to increase the RPM? Is it worth the money for a new prop for the few extra RPM's?

[OptiMax]

Drop the pitch to up your RPMs. If your RPM range goes up to 6000 and your only turning 4900, you should do something about it.

[TTfromBlaine]

what happens if you keep trimming it up until you get to that rpm range?

[DinkADunk]

Well you get 200rpm's for every 1" drop, from 4900rpm to 5500rpm is 600rpm so you'll need a 3" drop in pitch. Try a 15" prop. You should look at a prop dealer who will let you exchange prop's (a 16" prop and trimming it differently might work best as might a progressive pitch).