Sluggish top end

Hello

My 1987 '19 Bluefinn is running great after I had the carb rebuilt. The motor is a 2.3 liter with your basic Cobra out-drive. The problem I am having with it is that it seems to get boggy at the upper 4000 RPM levels. The motor sounds like it is straining or dieseling if that makes any sense. I have the recommended 13 1/4 X17P aluminum prop and it gets up to @ 32-33 MPH trimmed out according to my GPS. If I push it to 5000 RPM there is no increase in speed.

I am not a speed demon but I would like to get the motor to perform at it's best and it seems to work perfectly until I want to top end it.

I was planning on messing with the timing to see if I can eliminate the higher RPM strain or considering a prop with a slightly lower pitch or smaller diameter.

Has this situation happened to anyone else and how was it resolved?? Any help is always most appreciated!!

SH

Re: Sluggish top end

Sorry to answer my own post but last night I adjusted my timing, fine tuned my carb idle mixture, and topped off my tank with 89 octane.

I took my boat out after work and it ran flawlessly. No detonation, straining or knocking!! I did not have my GPS so I could not measure my speed but the motor sounded great. I looked through some older posts so a little tinkering paid off (so far)!!

Thanks

Re: Sluggish top end

Nice :joyous: