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Imagine a light aircraft soaring through blue skies with powerful yet fuel-efficient performance. This vision becomes reality with the Rotax 912 ULS/S engine, whose exceptional power-to-weight ratio is setting new standards in light aviation.

Rotax introduces its flagship product—the 912 ULS/S aircraft engine, a four-stroke piston engine designed for aviation enthusiasts and professionals who demand peak performance and reliability. Delivering 100 horsepower through innovative engineering, this engine stands out as the ideal powerplant for light aircraft.

The 912 ULS/S features a four-cylinder design with combined liquid and air cooling systems, maintaining optimal operating temperatures across all flight conditions. Its dry-sump forced lubrication system includes a separate oil tank and hydraulic valve lifters with automatic adjustment, significantly enhancing reliability and service life. Dual carburetors and a mechanical fuel pump ensure stable and precise fuel delivery.

Additional highlights include a dual electronic ignition system, electric starter, and propeller reduction gearbox—all working together to optimize power output and provide pilots with safer, more responsive control.

Key performance metrics of the Rotax 912 ULS/S:

• Power: 73.5 kW (100 HP) at 5,800 RPM
• Torque: 128 Nm (94 ft-lb) at 5,100 RPM
• Maximum RPM: 5,800
• Bore: 84.0 mm (3.13 in)
• Stroke: 61.0 mm (2.4 in)
• Displacement: 1,352 cc (82.6 cu in)
• Fuel Compatibility: Operates on gasoline with minimum MON 85, RON 95 or AKI 91 ratings, including leaded/unleaded variants, AVGAS 100LL, and ethanol blends (up to 10% ethanol)

Actual performance may vary depending on environmental conditions, altitude, and temperature.

The 912 ULS/S achieves class-leading power-to-weight ratios through meticulous weight optimization:

• Engine (with reduction gearbox i=2.43 and overrunning clutch): 56.6 kg (124.5 lb)
• Overrunning clutch: 1.7 kg (3.7 lb)
• Exhaust system: 4.0 kg (8.8 lb)
• External alternator: 3.0 kg (6.6 lb)
• Engine mounts: 2.0 kg (4.4 lb)
• Cowling: 0.4 kg (0.8 lb)

Rotax offers an engine configurator tool for personalized setups, allowing users to select preferred reduction ratios and accessories. The 912 ULS/S meets ASTM standards, with the iSc version holding EASA CS-E certification—validating its rigorous design, manufacturing, and testing protocols.

Through its combination of performance, lightweight design, and customization options, the Rotax 912 ULS/S establishes itself as a leader in light aircraft propulsion, suitable for recreational flying, training, and professional applications alike.