Thanks to you guys and my local dealer I adjusted the valves on all of my stihl 4 mixs today in about an hour. My local dealer gave me the clearance tool and showed me how to do it. Much easier than I had imagined. Both of my br600 blowers were way out of spec, hard to start and idled bad. Now both run like new. I would suggest to anyone that owns a 4 mix to do this.