[Benday]

My son has above engine with a bad backfire and does no run well, needing choke nudge every few seconds or so. Plan to reclean carbs (3) again using welding tip cleaner in pickup tubes. Any other suggestions regarding how to remedy problem. HAve changed gas, changed plugs, etc.Ben

[Waterbugtoo]

Could be a few things.Fuel problem, power pack double firing, trigger shorted out. Do an ignition component test and see if they show any problems.

[Trevor]

when all ells fails check to see if the timing is ok check the fly wheel key to see if it is in tack. but sounds like a carb issue when was the last time it was run?

[Capt Ken]

Being you said you was having to choke it ever so often, I'd guess the carb needs cleaning. The backfiring is really the carbs sneezing due to lean fuel mixture.