Possibly stupid question: recognising overheating

[Dr Moose]

I have an intermittent problem on POG, my air-cooled, and I'm trying to sort out what it is (with no mechanical knowledge!) Every so often, but nearly always going uphill I find myself losing power and juddering, nearly always in 3rd or 4th, almost as if the engine is choking. It only seems to happen when I've been driving enthusiastically, but once I pull in and let the engine idle, even for only a few seconds the problem clears.

Could it be overheating?

Otherwise I was wondering whether it might be anything of, too much fuel, not enough fuel, or gunk in the fuel lines.

Any thoughts for this mechanical dunce? (Other than finding a friendly local mechanic, or night school?)

Dr Moose

[Darrell]

Extreme overheating in my experience does result in a loss of power, but on an air cooled something has to be wrong like a lean mixture or wrong timing to cause overheating, and I believe it has to be properly wrong.

I suspect yours is suffering from the classic fuel pump issue.
The fuel pump is driven by a rod that runs off the cam. The rod wears and when the engine gets warm, a bit of expansion of the crankcase and suddenly you're not pumping enough fuel any more.

Most guys end-up replacing the manual fuel pump for an electric one which saves cranking so much to get fuel into the carb.
Dajwid has just done a conversion, check out his forum topic.