Won't hold RPMs

[erniex]

Hey Guys,

My 1973 85hp is giving me a little problem. I can not maintain constant rpms between 2000 and 3000 rpms. If I set the throttle to run between 2000 and 2500 it will drop back to 2000 and if I set it anywhere between 2500 and 3000 it will run up to 3000. Maintains rpms anywhere below 2000 and above 3000 but will not cruise at the in between rpms. Suspect that the carb needs rebuilding and the jets cleaning. Any thoughts or confimation will be appreciated.

EE

 

[Chris1956]

Re: Won't hold RPMs

Earnie, Is the boat planing at that speed, or just starting to plane? As a boat planes, the water resistance lessens, allowing the motor to rev up! The bottom line is that there are some speeds (and RPMs) that you simply cannot hold, due to planing issues and hull design.

 

[erniex]

Re: Won't hold RPMs

Thanks for the comment, Chris. Yes, the boat is on plane at 2000 and at 3000. Runs good at either. Just looking for the cruise speed in between. Accelerates smoothly through this range, just won't cruise within this rpm range.??????

EE

 

[Fenwick2]

Re: Won't hold RPMs

My buddies 90 hp does the same thing. I think it's the nature of the beast. He or we have to play with the throttle when bouncing in the waves. There could be some slack in the cable and throttle control I'm guessing. Do you have a screw you can tighten so the throttle is less likely or harder to move. Other wise we just apply pressure or pull back a little as needed to keep in that cruising range. Hope this helps.