rcdblink716

I know black isn't lean that's why i said it weird that it was. Unfortunately I don't have a wideband to accurately jet the carb. But I still don't think that's causing my stumble. It's a brand new carb and the accelerator pump is good, squirts plenty of fuel. I realize factory tuning is not that accurate but it should not have this bad of a stumble, it should not be that far off. Anyways, running rich or lea shouldn't cause it to pop through the carb either.

67mustang302

Popping through the carb is either valves or ignition timing. All you can really do is start back at square 1, adjust the valves then start retuning it, see if the problem goes away, if not, then look at ignition and carb, since that's the most likely culprit.

rcdblink716

Alright sounds good man, thanks man. I think it's valves becuase timing has been set and checked a few times.