prop

[fish sandwich]

I'm running a 115 merc 1992. I get about 5000 rpm on flat water but seems slow out of the hole. my prop is a michigan wheel 13.25x17. If I drop to michigan wheel 13.75x15 how much more rpm will I gain? engine recomendation is 5250 rpm max..Thanks ahead of time! Also forgot to mention that I run lake erie, so not alot of flat water running. would like to stay with michigan wheel prop so all i have to buy is prop. vortex is what its called. thanks again

[staylor]

...since I think the drop from 17 to 15 is a bit more change then the 5% shift you're looking for. I'd expect about 5300 to 5350 with the 15 pitch. The other thing to consider if you want hole shot is to buy the 15 but when running light on flat water just limit your throttle setting to 5250 rpm. Also, when you saw the 5000 rpm were you running with the motor trimmed out for best performance? If you were trimmed in due to water conditions you should re-test. since optimum trim may pick you up 100-150 rpm.

[fish sandwich]

thanks staylor. I was on flat water trimed out max to get about 5050 rpm. being in rough water alot i like your idea, i don't have to wind it out over 5250 in flat water. thanks again