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Old 05-15-2019, 12:03 AM
JOHN COOKSON JOHN COOKSON is offline
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Quote:
Originally Posted by tmcdonagh View Post
After installing a new gas filter and plugs she still runs rough for 1-2 minutes, coughing, stumbling and backfiring. She settles down nicely after that time. If I restart her right away, it runs normally. If she sits for 4-6 hours or overnight, the histrionics return. I have not been able to pressure test her on the water as of yet.
Thanks again!
This sure sounds like a sticky valve(s) to me. If you were able to run the engine at cruise RPM for an hour it might unstick it. Do you use MMO in your gas? Some* recommend outboard motor oil in the gas to unstick valves. I don't know the exact recipe.
*I think it was Dave N.

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