[Icee1976]

I fired up my KE100 for the first time since installing the overbore piston and the carb dropper was stuck open so It was at full throttle and I didn't know, but my problem is that when I panicked and killed the spark the bike was still firing, and I know for sure that it didn't have spark because the magneto key had broken off. I think it could be because the higher compression of the overbore piston because the crown of the piston was a bit higher and it is pretty tight when kicking over but if that is the problem then what do I do, any help would be appreciated and if anyone has thoughts to what else it might be please let me know.

 

[1981GPZ550]

Not unusual, I have seen this happen a number of times on perfectly healthy engines. Basically running like a diesel or glow engine.

 

[WFO-KZ]

Yes, I think 1981GPZ nailed it. Did you calculate the new compression ratio? Try doubling up on head gaskets to lower the compression.