can any help ive tried to adjust the carb. but it still back fires it has brand new air filter also

 

A backfire that appears for no apearent reason, usually indicates a lean condition.....

Is the new air filter the same brand and type that you have always run??? You may have a leak in the air intake somewhere. Could also be a clogged pilot (slow/idle) jet. Does it idle fine??? Just what did you "adjust" on the carb...the air/fuel screw????