[TR] TR4A - Advance Created Noise

[Randall]

Guy,
Someone else reported a similar noise, which turned out to be part-throttle
detonation caused by too much spark advance for the engine/fuel combination.

I'd try backing off the initial timing by about 10 degrees or so (by turning
the dizzy, not with the vernier), and see what effect that has.  The engine
won't run very well, but just keep it running with your toe and it won't
hurt anything.  If the noise disappears, then the issue is detonation.

-- Randall