The Ultimate Guide to the Rotax 914 UL Engine: Unleashing the Power in the Sky

Written By Kevin Baker  |  Engine


When it comes to light aircraft engines, the Rotax 914 UL stands in a league of its own. Developed by the Austrian company BRP-Powertrain, this turbocharged, four-stroke, four-cylinder engine has become the go-to choice for various types of aircraft, including light sport aircraft like the Evektor Harmony and Ellipse Spirit.

Engine Specifications

  • Type: Four-cylinder, four-stroke liquid-/air-cooled engine with opposed cylinders
  • Displacement: 1,211.2 cc
  • Bore: 79.5 mm
  • Stroke: 61 mm
  • Dry Weight: 78 kg with electric starter and other components

Design and Development

The Rotax 914 UL is a turbocharged development of the Rotax 912. It features a Garrett turbocharger with automatic waste gate control and dual Bing Constant Depression (CD) carburetors. The engine also comes with an integrated reduction gearbox with a ratio of 2.43:1, making it highly versatile for different flying conditions.

Performance Metrics

  • Maximum Power: 115HP at 5800 RPM (5-minute limit)
  • Sustained Power: 100HP at 5500 RPM
  • Maximum Torque: 106 ft-lb at 4900 RPM

Fuel and Lubrication

The engine can operate on automotive fuel with a minimum octane rating of 91. It features a dry sump forced lubrication system with an integrated pump and separate oil tank.

Variants and Applications

The Rotax 914 comes in various versions, including the 914 F series, which is certified to US Federal Aviation Administration FAR 33 and EASA JAR-E standards. It’s commonly used in light aircraft, homebuilt aircraft, and even military UAVs.

Maintenance and Time Between Overhauls (TBO)

Initially, the TBO was only 600 hours but has been increased to 2,000 hours, making it a reliable choice for long-term use.


What is the price of the Rotax 914 UL?

The engine is priced around $15,000, offering excellent value for its features and performance.

Can it operate on leaded fuel?

It’s recommended to use unleaded fuel to avoid additional maintenance requirements.

What are the cooling mechanisms?

The engine features liquid-cooled cylinder heads and air-cooled cylinders.


The Rotax 914 UL is an exceptional engine that offers a blend of performance, reliability, and versatility. Whether you’re flying a light sport aircraft like the Evektor Harmony or a more complex machine, this engine is designed to meet your needs.

About the Author

Kevin Baker loves everything about small planes, especially LSA. He's not just an enthusiast, he's also a flight teacher who loves sharing his passion for flying. Kevin uses his love and knowledge of planes to write articles, that make the thrilling world of flying exciting and accessible for everyone.