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« Last post by 33d6 on October 17, 2024, 04:47:12 AM »
I am curious. It wouldn’t be the first time I’ve seen a bronze Villiers carb seemingly bonded onto an aluminium manifold. Aluminium and bronze is not a happy electrolytic combination. Over a long period the aluminium corrodes away and sort of bonds into the bronze carb body. This is not really a problem as long as the joint isn’t disturbed and the owner treats both items as a single unit, removing both manifold and carb together and keeping them together but unfortunately this is a rare occurrence. They began life as separate items and the owner reasonably expects them to continue this way.
This may have been what’s happened here. It’s an ancient motor cycle, the manifold and carb have had a very long time together for electrolytic activity to occur, then along comes an enthusiastic owner who separates the two for cleaning and renovation finding the manifold “shrunk “ when the corrosion is cleaned off.
The same problem remains. How to fix it. I tend towards permanent solutions. I really don’t like the bits of shim or aluminium can route. In addition to my two previous suggestions I’d consider a thin sleeve. Trueing up the current stub and the permanently fixing on a thin sleeve with Araldite or similar. This would all depend on how sturdy the original stub is when cleaned up.