70 hp force rpms problem

[gibsrace]

i just bought a 20 ft sylvan pontoon with a 70 hp force it runs great but it tops out rpms to 6000 rpms to quick and will only run 13 mph it has a 12 pitch prop i think it needs more pitch and lower rpms my freind has a 24 ft with a 40 hp that will run 18 mph someone please tell me what to do mercury says a 95-3cyl force max rpms are 5250

 

[minstral]

Re: 70 hp force rpms problem

you should be running more like a 17 pitch prop...but you have to test each one so that you stay in the RPM range for the engine at WOT