Ed Anderson wrote:

What I was thinking about was whether the relative cool fuel mixture intake impinging on the hot rotor housing material might cause sufficient thermal stress to cause it to flake. Probably no practical way to test for that.   A more drastic test might be to heat up a coated rotor and spray it with water mist.

That would be more drastic than marriage!?

I don't have a spare rotor, but I do have various and sundry other pieces of cast iron lying around.  It'll be a relatively easy test to execute, just a pain to prep for.  I'll see what I can do with it though.

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