yeah but then you won't know if the carb has a air leak. Alot of times it will leak around the HSN or the front bearing but if you do it with the carb off then hold both open ends of carb closed hook up fuel line so you can blow into and put some soapy water around HSN and around the LSN make sure you slide on carb is open when you do it and watch for bubbles then you will find your air leak