Wandering RPMs

[jbrown64]

I have been having trouble with wandering RPMs under load. When under load the engine will be running fine around 1700-1800 RPMs then suddenly drop to say 1200 then jump back up and down.

I have changed the fuel filter and this helped for a bit, then it started happening again. I then changed the plugs and all was fine until I took the boat out again and the RPMs started wandering but not quite as bad as before.

The engine seems to be running fine in neutral.

[Antibes]

Do you have the PCV kit?

Mine did this with the PCV valve. I removed it and the problem went away.

[67c&ccorv]

When was the last time the carburetor was rebuilt/adjusted?

[sastanley]

Hi, welcome to the forum.

Sounds like an intermittent vacuum leak, or a fuel pressure problem. Any chance you have a fuel pressure gauge inline, or perhaps a vacuum gauge to the manifold?

I went out last week and the engine was purring along and died like I turned the key, about 200 yards from the dock..It turns out, I forgot to open the fuel petcock, but I was able to instantly tell what the problem was because my fuel pressure gauge read "ZERO" while my wife was cranking. Open the valve and we were off and running again.

[ndutton]

Originally Posted by sastanley

I went out last week and the engine was purring along and died like I turned the key, about 200 yards from the dock. It turns out,I forgot to open the fuel petcock, but I was able to instantly tell what the problem was because my fuel pressure gauge read "ZERO" while my wife was cranking.

The EWDS would have given you an audible alarm and amber warning light well in advance of shutdown. This is exactly why the system was developed.

Just sayin'

[JOHN COOKSON]

Any "slop" in the throttle linkage? Or is it nice and tight?

TRUE GRIT