Revving like a mother!

[Kpaul5257]

1989 Johnson 40 HP

Had fuel problems and replaced all the fuel lines, VRO w/ regular vacuum fuel pump. It had similar problems before but would stall at low idle unless I pushed in electric choke. Used to high rev before but not as bad.

i start it up and it idles around 1000 rpm and then if I give it a little throttle, it high revs between 4500 & 6000 rpm's even when I move the throttle all the way back down.

I can even shut it off and pull the key out but it keeps revving like crazy.
I just pulled the fuel supply line off to shut it off & then it killed it after a minute or so.

I also pulled wires from the primer solenoid while it was revving high but did not seem to change anything. I did not leave it disconnected very long as it was revving so high.

The prop has some dings on it & thinking about buying a new one today. Could that have Anything to do with the revving?

Thanks

 

[Kpaul5257]

Re: Revving like a mother!

Found this on an earlier thread on this website. Thanks...I'll put it in the lake!

Let me guess, you are running it out of the water, right? Or at least you are revving it up in neutral or with no load on the prop--right?

Don't do that!!!!

It is called thermal run-away or Dieseling, or whatever you want to call it. Run it like it was designed to run, on a boat in on the lake, and don't over rev it in neutral, and I'll bet it won't have that problem.