so my 4 wheeler was leaning out real bad and upon inspection i found gunk in the tank. i removed the tank and cleaned it out really well. i removed the carb dissassembled and cleaned it all out and put it back together. after that the 4 wheel will only run with throttle and you can tell its super rich. i have the mixtures screws only .5 turns out and its still too rich. What could have gone wrong. If you turn the fuel to off once it starts running low the bike will start idling right so i know its a rich problem. any help would be appreciated.