Three weeks ago today I purchased a new Stihl BR 600. Ran it for about 6 hours yesterday at full power. No issues yesterday or in the three weeks we've owned it. Put over 50 hours on it so far. Today, I go to start it and nothing. I thought maybe I flooded it, so I pulled the old plug, put in a new one, and it still won't go. Got it running but it was spitting and sputtering, white smoke pouring out the exhaust. Air filter is a little dirty. Every time I get it going, if I press the primer bulb every several seconds, it continue to run---rough. Took it to the dealer, they wanted to keep it, backed up for a couple of days, so I took it back home and have been trying to get it to stay running without me pushing the bulb. Any chance that the in-tank fuel filter may be clogged? What do you think is wrong with this extremely efficient blower? I used our BG85 today and my arm is about ready to fall off! Thanks for the help.