Misfire at cruise, popping/afterfire at 3000RPM

Phreakish said

I'd been following the thread for a while and didn't realize it was a sixpack until yesterday. Have you tried disabling the outer carbs to see if you can isolate it to fuel? Does the misfire only happen under load? Or can you replicate it in the driveway? If you can replicate it in the driveway, I'd hook up your timing light just to verify a spark and go from cylinder to cylinder and also at the coil to verify everything is firing - especially during the pop/backfire.

This is a strange one...

Click to expand...

its taken many turns but all for good reasons.
Go back to the very first post. The issue was described as misfires at moderate to full throttle in the range of 2800 rpm up while driving.

The timing curve was never fully mapped out as far as I can recall. I'm not convinced this is the cause as the description doesnt match, but is still something critical to do early on. IMO the mechanical timing ought to be ballpark correct before trying to hunt down issue tied to moderate to full throttle.