Loss of Power at 2000 rpm: RANDOMLY

[phoenix_fisher]

I just purchased a 1988 Bayliner with an 85 horse Force outboard. Had a mechanic check out the motor prior to purchase. He indicated that it needed a new impellar because it was running a little hot. It also needed a new lower unit gear gasket set. Since the purchase, 2 weeks ago, I got into the a shop and had repaired. The gear oil leak has not reappeared since the repair and the motor appears to be getting enough water when it runs. So......I took it to the lake yeaterday and ran it for about 5 hours. Off and on because we were fishing. Motor ran outstanding from the launch until about 3 hour into it. It had a tough time restarting after fishing but it always did start. Then on our way back to the launch, I started it and could not get it past 2000 rpms. No back fires, no smoking. IT was act like it was going to plane out then was bogg down and die.

 

[foodfisher]

Re: Loss of Power at 2000 rpm: RANDOMLY

Sounds like fuel starvation. Go through the system and look for flow restrictions. PS maybe a clogged fuel tank vent.

 

[phoenix_fisher]

Re: Loss of Power at 2000 rpm: RANDOMLY

Ok, I'll check it out. Also, one other thing, it ended up exceeding 2000 rpm, after I moved at 1200 rpm for 2 mins or so then throttled up and no issues. So it very well may be a fuel clog issue.

 

[phoenix_fisher]

Re: Loss of Power at 2000 rpm: RANDOMLY

Sounds like fuel starvation. Go through the system and look for flow restrictions. PS maybe a clogged fuel tank vent.

What are your thoughts if I tell you, when I put it in neutral it maxed out at 4000 rpm with no problem.?

 

[foodfisher]

Re: Loss of Power at 2000 rpm: RANDOMLY

In neutral is not a test. Under load, in gear, in water, will let you know if all is well. Max 4K in neutral is a sick engine. Suspect your mechanic, get a manual and do some testing on your own. Frank and Jerry are better suited to advise you further.

 

[jerryjerry05]

Re: Loss of Power at 2000 rpm: RANDOMLY

Do a compression/spark test.Is the linkage operating the way it should.Like opening the carbs all the way.Is it advancing the trigger all the way.Look for these two things.
At the top of the Force section is two threads look for a thread called linc and sinc by Frank.
Then start with the fuel system.The fuel pump diaphram might need replacing.
Do these things and get back with the results.Thanks food.J