[92xjunker]

He said it happens when he lets off the throttle. I'm going with after fires, pops on desel. It's quite common.

Just giving some info
Crossed plugs will also cause that.

[Yoyosten]

I'm stumped. I didn't mess with it today. It's 10 degrees. Next time I get the chance ill check for vacuum leaks. The gas is fresh.

[Yoyosten]

Got it out today. 65 degrees out. Started right up on choke. High idle even after choke off, probably from messing with it in the cold last time. I dropped it down to 1500 rpms and it got sluggish. It didn't want to stay it would just gradually run slower. It would only stay steady at 2000. #4 would spit every few seconds. I sprayed starter fluid behind the carb, slight jump in rpms. So I tightened them up more and fixed that. It seemed to run a bit smoother after that and stopped backfiring on decel. Still didn't want to idle consistently. Didn't leak at all during this, except of course, after I turned it off 1 and 2 started leaking again. I'll be ordering a float tool specifically for these carbs since obviously my eye and trusty square aren't accurate enough. I'll either rent or buy a sync gauge. I think that's all it needs.