'85 60hp won't rev past 3000

[Joe_the_boatman]

Took the boat out for the first time today. Starts fine, idles fine. Acceleration was a little "jumpy" and would surge. At full throttle, got to 4400 RPM, 27 MPH (so... underpropped?)

Then, engine cut off. Restarted, then would only get to 3000 rpm at full throttle, 12 mph. Sprayed gas (premix) in intake while running, and it sped up (so it's a fuel problem).


It's been sitting for a year, and hasn't been run on a boat in 4+ years.

It has 2 carbs. Could both high speed jets be clogged? What else could be the problem?

 

[CharlieB]

Re: '85 60hp won't rev past 3000

Dirty carbs, weak fuel pump or restriction in fuel line/filter.

Pump primer, if it helps then look into pump, lines and filter.

No change, clean carbs.

 

[Joe_the_boatman]

Re: '85 60hp won't rev past 3000

Yeah, I primed it while running out on the lake. Didn't change anything.

I'll double check my lines and filter though, also. Also checked my cables while underway; the throttle linkage on the engine was at WOT, so they're OK.

It looks like I got to pull off a lot of stuff to get to them. Any tips out there? I've done motorcycle and small engine carbs before.

 

[Joe_the_boatman]

Re: '85 60hp won't rev past 3000

Just thought I'd post a follow-up. Cleaned carbs out and put new gaskets in. Ran in the driveway in a bucket of water, everything looked good.

Got to 33 mph on the water (GPS) next day, at around 4800 RPM. Tach can't be trusted though, I just wanted to point out it revved higher after cleaning.

I think I was only running on 1 carb on that first trial.