My ATP seems to always be sucking for more air. It will spit and sputter when reaching higher RPMS any ideas why?

 

Check off the easy stuff first such as a blocked air intake,dirty filter,air box sealed ok,plus check that the tank vent hose and carb vent hose are open.If you think it might be fuel/carb related,pull the fuel line from the carb and crank the engine over. If the fuel pump,fuel filter are ok,should be a pulsating stream of fuel from the line. May need a carb clean along with a carb kit.Could even be water in the tank that settles toward the bottom,but picked up at higher speeds causing it to spit and sputter. Could even be clutch or belt related problem. Just a process of elimination until you find out what's wrong.