Sure sounds like the bypass is stuck open, the cover is scored / worn or the clearance wasn't set up right with the gears.
I agree blech on the grille but $700 for a beater body, I'd bite.
I think this is a common problem, mostly a product of modern fuel (ethanol) If I lay into my large bore 2g for a good pull my temps climb leading...
Do you have a solid ground strap/ wire between the engine and frame / bat -?
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