What ever happend with your problem and how did you solve it. I have a friend that has a 600 and he is haveing the exact same problem with the throttle up and it flaming out. If you go slow its fine if you go more than slow it gargles and flames out. Some times it shoots a little flame out sometimes it doesnt. Can you let us know what was your problem and how you solved it... I have artes turbines and he told me one time to shoot air through the fuel tube at about 80 psi to clear possible blockage in the burner tubes....

Thanks

David