I just bought a ‘71 BSA 650 Firebird Scrambler. Exhausts and frame are somewhat rusted, with some heavy oxidation on the aluminum cylinder head, so breaking it down. Service manual says "tap" the exhaust headers out of the cylinder head with a mallet. They've been soaking in WD40 for the better part of a week, and I couldn't knock these things out with a sledgehammer (haven't actually tried, but I'm getting to that point and not optimistic). In any case, I've tapped them with progressively greater aggression with a mallet, to no avail.
Any suggestions for getting these things out of the cylinder head so I can refinish them?
Also, any suggestions on what to do with the frame and exhausts, which are black? Black paint? Black powder coat? In the later case, I'm told that under high heat even the high temp powder coat will grey with time.
