FlymoreRC,
I had a simular problem on my gas engine (not a DLE 30) dying when I rolled to inverted. Discovered that the tygon pickup tube in my tank had become to stiff to allow th clunk to move to the top of the tank while inverted. Tygon tubing was only about 6 months old. I replaced the pick up tube with Hayes neoprene tubing and the problem is fixed.
Ralph White, Neoga, IL