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left side misfire and running hot


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engine-+4mm stroker, mild dune port, FAST head, stock carbs with twist throttle, +4 timing, K/N in box.Fatties. 

Last summer after stroker rebuild it was running great down a trail and just died. Found ground wire on stator broke off. 

New stator, and ever since the left side is issues. 

Runs 20F hotter at head and 40F hotter at exhaust port just idling. Misses alot at part throttle. it also has weak exhaust pulse on left side compared to right through out entire range. Runs great at WOT. 

Throughout about 10 hours of riding, adjusting, checking, replacing things it has blown the left spark plug out 3 times, good threads in head, new head. new plugs, does not matter.

New V4 this weekened, no help. 

No intake leaks, no cross tube leaks.

swapped plugs and wires left to right-no diff

Swapped carbs left to right and the miss tends to go away, but still bogs in mid range like needle jet, changed that to all five positions and it did not help. swap carbs back and misfire is back on left side. Of course been through carbs several times. Checked float height and intake air screws, needles. 

Compression is 128psi left and 130psi right at sea level, which is the same it was after the rebuild so no worries there.

 

Out of ideas. 

Any one else have some?

Thanks in advance

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Not sure what you mean by pressure test results. 

I have stopped running it now since it popped out with a new plug. First two times I questioned my install method of a used plug(crushed washer) on a new aluminum head.

Thanks for helping

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