I found this moped for sale at a yard sale for $10 because it didnt run. After I got it home, disassembled and cleaned the carb, added a new plug and battery, It only runs with the choke on (and runs OK just no top end). I thought it needed an air filter (As it was absent) to increase resistance. Added that with the same results. The air screw is 1 1/2 turns out and moving it around doesnt have much affect... anyone have any thoughts? Thanks!