The Rotax 503 is a 37 kW (50 hp), inline 2-cylinder, two-stroke aircraft engine, built by BRP-Rotax GmbH & Co. KG of Austria for use in ultralight aircraft.
Rotax 503
A Rotax 503 mounted on a Flightstar II ultralight
The prototype Blue Yonder Twin Engine EZ Flyer is powered by two 503s in pusher configuration
Air Creation Racer ultralight trike with Rotax 503 mounted up-right. Below the muffler is the smaller after-muffler.
Rotax is the brand name for a range of internal combustion engines developed and manufactured by the Austrian company BRP-Rotax GmbH & Co KG, in turn owned by the Canadian Bombardier Recreational Products (BRP). Under the Rotax brand, the company is one of the world's largest producers of light piston engines.
Rotax 912 installation
Rotax 503