1.The L550 engine is a horizontally opposed four-cylinder, two-stroke, air-cooled, carburetor-fueled piston engine with a displacement of approximately 550 milliliters. This engine model delivers a power output of 37 kW, with a maximum speed of 7500 rpm and a dry weight of 16 kg. It is primarily used in lightweight aircraft such as drones.

2.Currently, a more powerful electronically fuel-injected version of this engine has been developed based on the original model, and a national invention patent has been filed for it in China.

(1) Multi-point electronic fuel injection technology has been developed and applied for the first time in a two-stroke aviation engine, and an exhaust resonance system has been integrated into the electronically fuel-injected engine. The combined use of these two technologies enhances the engine's power output at the rated speed—specifically, by 10% for the L275EF and 15% for the L550EF. Fuel consumption is reduced by 20%, improving fuel economy. Coupled with ECU electronic management, the engine can operate continuously for over 48 hours.

(2) Innovation in the multi-point fuel injection mechanism. The L275EF is a two-cylinder piston engine equipped with two independent intake systems, while the L550EF is a four-cylinder piston engine featuring four independent intake systems. The advantage of developing independent intake systems lies in preventing interference between combustible mixtures in different cylinders, ensuring more uniform mixture distribution. This facilitates better combustion and balanced operation across all cylinders.