Bonneville America Forums Forums General Motorcycle Forums Other Bikes 1971 BSA Scrambler stuck exhaust headers

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.

A friend of mine is really big into restoring old British bikes. Checkout his website and send him an e-mail with your questions. Eventually he will get back to you.

Joes_Garage

Tom

Use patience - the tap method works. Keep soaking, apply a few taps per day and they'll free up. For any frozen fastners, a good tool to have/use is a good ol' fashioned impact driver - The kind you tap with a hammer. Use the same approach - soak, tap and patience. Those parts have been on for decades. It will take some convincing to get them to budge. If you take the slow approach, you'll be likely to save some heartache and misery. WOrk on other parts while the process unwinds.

A good brass punch will be your friend on projects like this also. You can wail on it and not be afraid of it punching through a fastener. They are hard to find, but a brass carriage bolt from a marine dealer works as well.

NO PUNCH! pipedr has the right idea. The more agrresive part is bad you can crack the head. I restore antique Brittish bikes myself. If you have a big enough pot you dont care about take the head off with the exhaust attached and put it in the pot filled with motor oil and heat on a stove type burner. heating it in the oil slowly will prevent warpage (also works well for fitting pistons if you know how)as it expands the oil works into the area around the pipe as well as the aluminum will expand before the steel. Should make it easyer to pop loose. Just remember patience and not too aggressive.

I might add very difficult to do but is possible. Kind like pushrods on a Norton! LOL

If the exhaust Headers are to be replaced with new ones just saw them off as close as possible and then use a dremel or collapse them inwards with a punch. I imagine the head has corroded up swageing them in.

Try Liquid Wrench instead of WD40. It penetrates much better.