Cutting in and out at peak RPM

Often the bog stock plug may break down at extreme pressure/revs.

You have to heat the engine to operating point and it is a good it idea to try to heat the sophisticated plug a little before insertion.
 
Thanks Blaaster, I tried a br9eix iridium and it didn't do it, welded the ball in the clutch trying
it thou.
Small price to pay.:D:D:D

When you replace the ball, coat it with white lithium grease, common garden grease is not good enough!