Got it all back together finally. It starts! But it's backfiring like crazy. The idle is all messed up. The throttle at the low end is very spotty. If I can rev it over 4000 it starts to sound smooth, but not even near normal. Backfiring to the point of sounding scary. Also getting a burned something smell.

Brand new gas

New Tank

Carbs were just sprayed and cleaned, but only through the float bowl. I did not overhaul carbs.

Throttle cables are iffy. I reattached and tightened, but it could be off. I didn't mark where the nuts threaded to

As far as I know, the airbox is attached properly.

There is a little bit of Seafoam in the tank.

I used deep creep on the carbs

Anyone have any ideas before I tear the carbs off again? It HAS been sitting for a year. I thought a new tank and a cleaned carb would remedy that.