Firstly, unscrew the needle until it's flush with the black housing, then, hold the carb shut with your fingers (well as far as your idle adjustment will let you, (1-2mm open)) Then screw in the LSN until you feel a slight resistance compared to normal turning, your LSN is now closed. DO NOT OVER TIGHTEN THIS NEEDLE!!!!!! you will kill the jet where the fuel goes into the carb.