How to fix damaged threads in a YT175 head, the exhaust threads?

[bobotech]

I have been working on my YT175 and finally got it to fire today. However it was leaking exhaust fumes like crazy from the joint where the donut gasket and the pipe meet. I tried tightening it down a little more and the bolt then pulled the threads out of the hole. Crap!

What is the best way to fix that?

[Vealmonkey]

Several ways to fix. Use a thread repair kit/helicoil kit, drill and tap to a larger hole. Reweld the hole and redrill and tap. Or just drill and tap to a larger hole and make the hole bigger in the exhaust flange as well.