The BME 50 is putting out a little more power, but not alot. I have the BME 44 is a 15 1/2 lb Extra and have considered switching it to the Moki 2.1 .

The BME 50 will spin the 21x10 Mejzlik at 7100 or so. The Moki will spin the 20x10 Mejzlik at 7600. There is about 2.5 lbs more of static thrust in the BME than there is in the Moki. Both are in the 27-29 lb's of thrust range.

Personally, I'd go with the moki for glow convenience, one battery, no ignition noise, less hassles and a far smaller purchase price. The Moki that I have is an AWESOME glow engine.

-Mark-