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Well-Known Member
Supporting Member
Mar 19, 2022
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Huntersville, North Carolina
I have been chasing down a gremlin for 2 weeks now with no luck.

During run up I started getting an afterfire in the form of one to two pops out of the exhaust (thanks for clear floorboards) predominantly on the left mag at 1800rpm. Tonight I ran it up to 2200 and found it turns into a constant afterfire on both mags. I'm confident the mags or ignition is not the culprit (new leads, and fresh OH 20 hours ago)

- I've cleaned (before & after photos), tested, resistance checked, rotated and gapped - they were mostly sooty but not terrible, not great either
- I've verified the timing is spot on 25 degrees BTDC
- Borescoped and compression checks were BAU
- Runs smooth, starts easily, and is making power
- Raven 4 into 1 exhaust (5hrs), not sure if this is just a byproduct of a 4 into 1 set up?

Has anyone else experienced this OR just learned to live with it?

I'm thinking this is a symptom of running slightly rich but am hesitant to make adjustments (PS5C) to the idle mixture with how well it runs otherwise.

I'd be grateful for any tips you all may have!


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