Back firing

[T.Hanson]

Idle, rev it to 1500 - 2500, I can hear off throttle popping, (backfiring?) in the cat. Rrrrrevvv, poppity pop. RRRrrrevvv, poppity pop pop.

Now what did I do? I know it's timed right, valves adjusted ten thousands, twice, correctly.

[Peter Florance]

It's unburnt fuel most likely, like someone adjusted your throttle switch to not engage at idle.

[T.Hanson]

Indeed. My logic list rolled my eyes up to look between my eyebrows, with the tin woodsman's index finger ( if I only had a brain ) gesture to my temple. "Whats did I do'd that's not right ? "

Maybe try adjusting the idle cutoff switch again, as reading the L jet FAQ seemed to make it more important than tonsils.

I always like when doctors take stuff out ( tonsils, appendix, etc. ) and say you don't need it. Right. God being the original engineer.

So I did, adjust the idle switch. No more crackling of throttle.

Thanks.