The initial versions of the M-11 suffered from a short service life of only 50 hours. The basic M-11 engine had a power output of 100 hp (73 kW), the newer M-11D variant was higher at 125 hp (92 kW). The ultimate version, M-11FR, introduced in 1946, increased power output to 160 hp at 1,900 rpm on takeoff and 140 hp at cruise and had provisions for a variable-pitch propeller, accessory drive (for vacuum pumps, compressors, generators, etc.) and featured a floatless carburetor.