Scooterotica

Could it be air leak causing pre ignition. Had similar problem couple of years ago . Changed everything electrical / crank- top end & backfiring continued. Only thing NOT changed was the engine case which is early jet200 used for the first time.
First engine I ever gave up on( it's still on a shelf in the garage)
My thinking at the time was a hairline crack in the crankcase area, or not sealing properly on the inlet side......

Had a similar issue and it turned out to be a crack in the flywheel........certainly worth trying another flywheel

Sorted! After eliminating everything electrical, I looked at fuel as the cause. I changed the tap, fuel pipe and swapped the cheapo Koso 34mm for a correctly jetted 34mm Dellorto and it's all good. I followed my son in my van and it was pulling away from me at 80mph. He's as happy as Larry now, and so am I. Thanks all.

Good dad, lucky son


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