A short while ago during all these carb problems I went over to Kevins and we stripped the carb right out.
The jets appeared to have corrosion/rust on them. Only a little time ago I had these out and they were fine. Blame E10.
Today after a carb rebuild on the CAP 232 a few months ago and waiting on fine tuning, I thought I might just take it outside on my grass and get it running. Fire up, run a split second and backfire die. Not back to fuel starvation again/blocked jets? Anyway after checking the carb in situ I thought I might as well check the plug. Corroded and the oily rust had virtually short circuited the electrodes. Water in fuel
Ruddy E10. Be glad when the last of it used up in the mower. Gotta be VPower or BP Supreme next time round,