what should this be running? genal idea

[sun burn]

got a 16x38 jon boat with a 1989 15hp force pushing it, it might top out at 16mph if lucky, with about 300 lbs in boat...why i am asking this, heard story's of force being bad on firing problems just wording if this is a little slow and think i could use a higher pitch prop (if i could find one) rpms sounding little high at wot and another jon boat bigger and wider than mine had a 25 Johnson and just runs off and leaves me like i am at idle. mine does have a good hole shot, but thats all its got. also dont plain out could all this be prop related? or could be getting fire on one cyl. plugs look good or look like they both get fire

 

[sun burn]

Re: what should this be running? genal idea

ok i know for sure got fire to both plugs.so prop maybe ? and on the air screw on the carb is backed out little over 3/4 of a turn is this about right?

 

[fucawi]

Re: what should this be running? genal idea

you can never sort out props unless you have a rev counter to read your WOT rpm...if this is too high you can increase the pitch.......2 inch change in pitch changes revs by 400 ..suitable electronic tacho for the plug lead on e bay ....

You carnt expect a 15 hp to go anything like as fast as a 25 hp