Spark plug insulator around electrode broke off in the motor

[TGM_OFFROAD]

Originally Posted by Zman

I do not know what heads you have and if they have been modified. My point is that squish is independent of compression ratio.

I would assume that a stock unmodifed head should be fine for 100 octane fuel. I have been on this site for many years we have come across some factory built bikes that were machined differently than others and some bikes that were shipped with different parts.



Your detonation situation seems out of the ordinary so I would assume nothing.

It is really odd, it had done it with my stock gp head, rk tek head set for pump gas and the s3 low compression and high compression head. It passes a pressure test with flying colors so no air leaks. My only other thought is timing which would have to be a cdi issue on this model. Hopefully I can get a new one tomorrow or wed.