Rotax 447 UL
Rotax 503 UL
Rotax 582 UL
Rotax 912 UL
Rotax 912 ULS
Rotax 914 UL

Shown here with air box, external alternator, hydraulic propeller governor and air guide baffles.

Rotax 912 ULS DCDI 100HP*

  • 4-stroke engine specially developed for recreational aircraft. Also exists in a certified version: Rotax 912 S.
  • 4 horizontally opposed cylinders, "boxer" configuration
  • Free air cooled cylinders, liquid cooled cylinder heads with integrated pump and expansion tank
  • Dry sump forced lubrication with integrated pump and separate oil tank
  • 8 valves, automatic adjustment by hydraulic valve tappet
  • Dual Capacitor Discharge Ignition (DCDI) with RFI noise suppression
  • Two Bing Constant Depression (CD) carburetors
  • Mechanically driven diaphragm fuel pump
  • Integrated heavy duty electric starter
  • Integrated reduction gearbox, ratio of 2.43:1 with slipper clutch standard
  • Various liquid and oil radiators available
  • Many option available such as: Vacuum pump, external alternator, hydraulic propeller governor
  • Operates on automotive fuel with a minimum octane rating of 91 (Canadian standards)
  • Time Between Overhauls (TBO): 1500 hours*


Maximum Power*
(5 minutes)
100HP / 73.5KW @ 5800 RPM
Maximum Power (sustained) 95HP / 69.0KW @ 5500 RPM
Maximum Torque 94ft-lb / 128NM @ 5100 RPM
*100HP maximum power when optional air box and tuned exhaust are installed.

Combustion Chambers

Bore 3.31" / 84mm
Stroke 2.40" / 61.0mm
Displacement / 1352cm
Compression ratio 10.5:1


Engine with carburetors 124.7lbs / 56.6Kg
Exhaust System 8.8lbs / 4.0Kg
Air Box 2.9lbs / 1.3Kg
Air Filter 0.7lbs / 0.3Kg
Liquid Radiator 2.2lbs / 1.0Kg
Oil Radiator 1.1lbs / 0.5Kg
Regulator-Rectifier 0.2lbs / 0.1Kg
Installed Weight 140.6lbs / 63.8Kg
Weight/power ratio 1.41lbs/HP / 0.87Kg/KW


Information Sheet 912Sinfo.pdf / 436Kb / Adobe Acrobat format
Performance Graphs 912Sperf.pdf / 14Kb / Adobe Acrobat format
Technical Drawings 912Sdraw.pdf / 537Kb / Adobe Acrobat format
Manuals Visit
Service Documentation Visit