Pegasus fell down

Pegasus 40 fell down today by my mistake, relatively low altitude and unexpected motor stop after spinning maneuver in the worst timing, should I control it by aileron, but I did it by elevator control. Fair judgement in the critical moment separate life and death, though I have some self-confidence to avoid any accident, actually I could not!
Motor stop phenomena has been repeated after spinning and 1/4 bulk of silencer was filled with fresh fuel, how come?
When spinning is performing, the fuselage is rotated and twisted with the center of gravity point, some centrifugal force is applied at the fuel tank position then fuel goes to the muffler through muffler pressure tube line resulting new fuel fulfill the muffler.
Checking the muffler pressure nipple, hole size of OS 46LA nipple  is larger than recent ENYA. Is there any possibility of motor stop that fresh fuel flowing backward from fuel tank to motor muffler inside?
I should know the reliable conclusion about this bizarre phenomena that led my Pegasus to destroy. Trial experiment must be performed by myself ASAP!