i picked up a 83 atc70. guy told me it was parked last year due to broke pull cord. i replaced the pull cord, cleaned the carb, new plug and checked valve clearance. didnt have the air filter foam when i got it and local shop didnt have one so i got some 5/8" uni foam and doubled it up where the original would have went. the baffle/ arrestor is also cut out of the muffler but endcap is on. it starts and runs but runs best with pilot screwed all the way in and when playing with the throttle the idle is erratic. it revs high sometimes and low others. i was thinking maybe the throttle cable is hanging up but with it idling normal at times with the pilot all the way in and the idle screw actually working im kinda doubting its the cable. any suggestions? sorry for the long post but the more info the better. thanx