Mysterious shutdown

[Steplift 72']

Originally Posted by nymack66

I took the V out in real choppy waters this weekend (small craft advisory was in effect) .
It was indeed a pleasure watching the V slice through the waves and tasting the salt of the ocean, I stress the crap on the Arjay transom no leaks no problem.
During my run the engine, Evinrude 1987 140 looper just shutoff at 5500 RPM, the primer bulb was hard as a rock and the engine started right back up no problem.
On a run previously the RPM seems to drop to 4500 then jump back to 5500 then all seems well there after, now this weekend it rear its ugly head again.
Do I have a problem brewing like a bad pack or something ?
My fuel sender was acting up the new gauge rocking back and forth, I replaced it and lubricated all connectors with electrical grease and corrosion inhibitor, thinking may be a bad ground or something..
Any ideas ?

Check the ignition ground on the back of the cylinder heads. Each of my 140 loopers did the exact thing you mention and by luck I found an ignition wire ground corroded inside the crimp connector. It pulled away when touched and was making intermittent contact. Before it shut the motor down it had apparently interrupted the ignition momentarily on the previous trip. I love the 15cent solutions....doesn't happen that often.

[nymack66]

72,
I will take your tip into consideration also, I have brand new wires throughout this set-up you name it and its new down to the key switch, but still I am not ruling out an electrical problem just yet,however his fuel tank had me worried about this vent issue from day one.
Thanks

[spareparts]

if it acts up again, just loosen the fill cap and try again, that should tell you if its the vent. If it runs good with teh fill loose, tighten it back up and see if the problem returns

[nymack66]

I took the Boat out today and ran the crap out of it , Happy to report its a fuel issue, As long as I kept the bow down it was ok half way up on a plane the primer all goes flat! I will have to insert an new vent hook up on the front of the tank.
I will post pictures when this is done , for now the tank is below 1/2 as long as I punch it up on a plane it runs just fine 5300 rpm right on.
Its amazing if I held it on 3000 rpm with the bow up the bad boy shuts off completely starts right back up.
I now remember this was exactly my initial thought as I flip the tank around.

[bradford]

Glad you figured it out bro.