Pull the intake hose off the carb, start it up and watch the slide in the carb throat it should move up and down sounds like it may be sticking. If carb cleaner doesn't free it up then the diafram could need replacing. Backfiring on decel may be a bad exhaust gasket of crack in the header pipe.
FLOYD, SANDI & Sadie is the co-pilot. 05 660, 3000# VENOM WINCH, LED headlight Mod, 12' led light bar RZR seats, Resi shocks, SunF 26 X 9r X 12, CUSTOM PAINT(the rescue chopper can find us know)
"REMEMBER, SPEED KILLS, BUT IT WILL BE THE ONLY TIME YOU'LL DIE LAUGHING"