Turn the screw labeled "T" clockwise if the idle is too low and you require a higher idle speed.
Turn the screw labeled "T" counter-clockwise if the chain on a chainsaw moves when idling, or you need a lower idle speed on other equipment.
Fine tune the T-screw after a few minutes use to complete the repair. Turn the screw so that the engine runs smoothly at idle, and also when running. Re-check idle after turning the screw while the engine is under load. Keep plenty of leeway between idle and the chain rotating---the chain musn't creep forward.