Head Porting

[motomxman450]

Hey guys I have been reading around and on a couple of topics they talk about epoxy in the head, it may be a noob question but can someone please explain.

[speedfreek]

Epoxy is used to change the port dimensions to improve velocity or fill in imperfections which would also improve velocity. I've never heard of anyone using epoxy in an atv. Sometimes it is used to correct someone's bad port work.