Seriel #62JU233 Motor misfires on 2 cylinders. I have new fuel, new filter, new plugs and clean carbs. Compressiion 110 psi +or- 2psi all cylinders. Cold engine starts and runs fine for about 1 minute and then won't idle and misses terrible on cylinders 2 and 5. 2,5 plugs don't get dirty. Thanks!
