Isn't the higher the pitch it power not speed?
See, I've asked on a couple sites and I'm really confused. So a 19 or a 20 pitch would be good?
I know this is later than your fixing your problem but rev limiters like I have on my 2002 115 2 stroke can give you the wrong answer as you found out. Had you not had the rev limiter your RPMs with your 15P would have had revs over the upper limit of 6k RPM.....I'd bet. Then it would have made sense to increase pitch and gain/ maintain RPMs simultaneously until the increased pitch loaded the engine enough to pull the RPMs down below the limit of 5250....service manual number.
