KENIG Piston problem

[Hahnda]

Looking for a little input on these. I have a CL77 in the shop that has them. I can actually read KENIG on the top of the piston through the plug hole.

I am building the bike but someone had already rebuilt the motor. The owner told me who but I can't remember. Anyway when I run the motor the piston is making contact with the spark plug, just barely, but enough to close up the gap to zero.

Has anybody used these before? Any input?

[Hahnda]

I tried a different plug and now it doesn't happen. Maybe the index of the electrode just happened to be in the right spot to make contact.

It was only the left side. 3 times I pulled the plug to reset the gap. It would start fine then start backfiring on the left side. Pull the plug and zero gap.

[G-Man]

Kevin

I've seen HC pistons with a little divot ground out where the spark plug sits. I thought it was to get good flame propagation but you may have discovered the real reason.

G