Dave Hamblin
(formerly DaveH on old site!)I was flying it (with my CFI) the third time it did it (after again being proclaimed healthy by a shop that "fixed" it). It started as a perceptable vibration in the yoke to suddenly back firing and vibrating to the point I initially thought I had chucked part of a propeller.
George fiddled with the prop/mixture and got it down do a reasonable level (though still back firing loudly) while I scooted for the airport.
Last time it did it, it barely made enough power to climb at all. Its a 4 cylinder Mooney M20E.