When my 2010 AC 650 is warm up and I shut it off, it sometimes back fires. Can someone tell me what causes it too back fire.

 

CountryCat.com

 

item #16 is fuel mixture screw alot of atv are set pretty lean from factory to pass the emissions for goverment..an sometime this can cause an backfire..If you want try this test out the redneck way it could tell if this is your atv problem...let atv get normal temp while idling put hand about 2 to 3 inches from end on exhaust an if it burns or stings your hand then the mixture screw or [PILOT SCREW} is correct name but alot of time this screw has welch plug[plug or limiter cap] over the screw head so cant be readjusted..may have to remove plug an opened up screw bout half to an full counterclockwise turn then recap back..Also if hand doesnt stinged or hot the could have baffle in muffler burning out an sometimes the baffle block exhaust from existing muffler an back fires to move baffle so can exhaust vapors out, If atv has an high idle sometimes this could cause an lean fuel burn an cause an backfire.