Kcampbell3
Recruit
- Joined
- Jan 23, 2017
- Messages
- 1
Hey guys, I have been working on this issue for over a year with motor and cannot for the life of me figure out whats going on. This engine is on a 18ft fiberglass bass boat. Only when in use on the lake (under pressure) and after getting on plane the RPMs jump up and down very dramatically from 4000rpm to 2500 - 3000 to 4500 rpm and so on. Its as if its bogging down the jumps back up to where the I have the throttle. If i then stop, come to complete stop it boggs down running at low RPM and will not go back onto plane until it randomly decides to start working again... When in low RPMs during the issue they dont sound bad like its choking or sputtering it just wont continue its revs to increase the RPMs. somedays its very bad, other days it does it for 30 seconds and is fine the rest of the trip.
Here is what i have done so far:
- replace bulb and full gas line
- replace fuel filter
- fully removed fuel filter out of the equation for a moment. (no change)
- cleaned all 3 carbs (not professionally or replace the jets.. just cleaned)
- took the boat for someone to check out the VRO jump
- he replaced a membrane inside that was torn
- this did not resolve so i disconnected the oil completely and pre-mixed gas. No result change
-took off exhaust manifold, cleaned and replaced gasket to make sure no water was getting into cyliders
- replaced a bad temp gauge
- compression tested all cylinders ~90 PSI on all (within normal)
- replaced and tested all spark plugs
any ideas would be helpful thank you in advance.
Here is what i have done so far:
- replace bulb and full gas line
- replace fuel filter
- fully removed fuel filter out of the equation for a moment. (no change)
- cleaned all 3 carbs (not professionally or replace the jets.. just cleaned)
- took the boat for someone to check out the VRO jump
- he replaced a membrane inside that was torn
- this did not resolve so i disconnected the oil completely and pre-mixed gas. No result change
-took off exhaust manifold, cleaned and replaced gasket to make sure no water was getting into cyliders
- replaced a bad temp gauge
- compression tested all cylinders ~90 PSI on all (within normal)
- replaced and tested all spark plugs
any ideas would be helpful thank you in advance.