While the tank was off, I noticed four holes in my cylinder head. Each hole is by a bolt. The metal in those areas appears thin. I was thinking I would just remove the head and JB Weld those holes.
Miker,
I can't say if epoxy is the right cure or not, but there are much better epoxies made for high heat applications. I like JB Weld, too, but it does have limits. Contact them, and ask if they have the right epoxy for you. Contact Permatex and 3M as well; you may find an excellent answer from them, or they may tell you what product you need, if they don't make it.
If you need an all-new petcock, RPM has them.
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