pretty sure I found the culprit. weirdly it didn't smoke more on the rh side but I think it was just enough to foul the plug. as said, the airgap was large, adjusting it down helped, but probably juat by giving a better signal to fire thr plug better to help prolong the fouling.
the wear it's bad enough to feel the curve of the grooves. its wild. I rebuilt this motor a year ago. weirdly don't remember this being that bad. luckily I had a spare. so, not the ignition, not the carb. I think this might be the downside of running synthetic trans oil. can't really tell when the seal is seeing on the plug.
the wear it's bad enough to feel the curve of the grooves. its wild. I rebuilt this motor a year ago. weirdly don't remember this being that bad. luckily I had a spare. so, not the ignition, not the carb. I think this might be the downside of running synthetic trans oil. can't really tell when the seal is seeing on the plug.


also, that arm is made for a 350. the wider adjuster slot is on the LH side . 400s have that on the rh side.