Gas DS backfiring at full throttle

[Savannahdad]

I have a 94' DS with I beleive an FE 290. I just pulled apart the carb and fuel pump and cleaned then re-assembled. Replaced fuel lines, filters and cleaned the tank out three times with fresh water. Ever since this cart has been in the family ( I just inherited it after it sat for two years ) it has always backfired when you pressed the accelerator to the floor. Is this the govenor or the rev limiter? Do these engines even have rev limiters? I'm certainly not wanting to turn this engine up to where I have to worry about overheat issues, however, I do want to dial the engine in to where I reach it's full potential. I want it to run like it was meant to and not backfire its way all around the neighborhood. The "sweet" spot is about an inch back from full throttle. Any and all help would be much appreciated, I am new to the forum and already have found tons of useful tips.