Wondering if anyone else has ever had this...... I have a DLE 55 in a plane and have been flying in wonderfully. It has very little burble and runs great. The curious part is that if I find the right spot on the throttle where it has a little burble, then flip the plane inverted, the burble stops completely and it purrrrrs like a kitten.

Any of the pro's care to lend a thought?? My other 55's have no burble at all. Thought maybe the input on this may also help some of the guy's trying to tune their 30's.

Thanks!