2006 Harley Davidson XL 1200 C Sportster Custom "knob glass spark" Questions

...glass beading machine but you have to blow them out very well before reinstalling them. I also put a little anti-seize on the threads to keep from damaging the spark plug hole threads. Try installing ...

knob is pushed back in. Last but not lease, could also be an electrical related issue due to the bike warming up and causing a short or open as stuff expands. I would change your plugs, then drain the