Originally Posted by 60wag
Isn't the "coasting richer" circuit in the carb supposed to add a fuel to reduce the lean condition on decel? The rest of the carb may be performing great but it may be worth checking the function of the one circuit. I think it's entirely internal on the carb and can't be plumbed wrong with tubing.
It might be the same issue causing the loud pop on Telly's 40 on shutdown.
My issue is an A-B comparison vis a vis the carb. My issue was not present with the prior to the motor rebuild, and is present after. I installed the carb the day before I drove toward Moab and had no issues with backfiring upon negative acceleration during that drive.
As I wrote, I need to (1) check valve adjustment and (2) replace the muffler with holes and possibly (3) check all the emissions subsystems before I come here and ask for advice.