when I turn my cruiser off the little f motor is so baddass it just keeps running for another 5 seconds then grumbles and gives up! woo it impresses the ladies!
what causes engine run-on?
- Thread starter Trashcanman
- Start date
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There are two causes that I know of and I am sure there are more that someone will chime in on. First, and probably most likely, you have a heap of carbon deposition on your piston heads from years of faithful combustion. This carbon gets red hot during operation and will stay red hot for a bit after you turn off your engine. That red hottness acts as a spark to ignite the incoming fuel for a bit to keep the engine running. Secondly, engine timing could have a part in it.
Hello Trashcanman, engine run-on is commonly caused by excess fuel in the combustion chamber during shut-down. It gets there via high idle speed, overly-rich idle air/fuel mixture, or, as PinHead said, leaking idle cut solenoid o-ring leaking. A quick test should I.D. the prob. Drop the idle speed and turn the engine off - should result in no run-on. No fix: lean out the idle air/fuel and turn off. No fix; carb internals need attention. Good luck! Dan
wouldn't this depend on what year "F" he has? I didn't think the older ones had a fuel cutoff selenoid.
not sure, let the experts discuss, but isn't carbon buildup another possibility, causing pre and post ignition by the superheated carbon buildup on the piston tops
