The Zenoah G-25 is a single cylinder,

two stroke A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being completed in one revolution of t ...

, carburetted aircraft engine, with optional

fuel injection Fuel injection is the introduction of fuel in an internal combustion engine, most commonly automotive engines, by the means of an injector. This article focuses on fuel injection in reciprocating piston and Wankel rotary engines. All comp ...

, designed for use on

ultralight aircraft Ultralight aviation (called microlight aviation in some countries) is the flying of lightweight, 1- or 2-seat fixed-wing aircraft. Some countries differentiate between weight-shift control and conventional three-axis control aircraft with ailer ...

Cliche, Andre: ''Ultralight Aircraft Shopper's Guide'' 8th Edition, page G-8 Cybair Limited Publishing, 2001.

Development

The Zenoah G-25 is equipped with single

capacitor discharge ignition Capacitor discharge ignition (CDI) or thyristor ignition is a type of automotive electronic ignition system which is widely used in outboard motors, motorcycles, lawn mowers, chainsaws, small engines, turbine-powered aircraft, and some cars. It w ...

and a single Mikuni slide-type

carburetor A carburetor (also spelled carburettor) is a device used by an internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the venturi tube in the main meteri ...

. It is equipped with a

recoil starter Rope start (also called pull start or ''rewind start'') is a method of starting an internal combustion engine, usually on small machines, such as lawn mowers, chainsaws, ultralight aircraft, small outboard motors and portable engine-generators. A ...

system or optionally electric start and a 2.5 or 2.8:1 belt reduction drive. The engine runs on a mixture of unleaded auto fuel and oil. Producing at 6600 rpm, the G-25 competed in the early 1980s ultralight powerplant market against the similar

Rotax 277 The Rotax 277 is a , single-cylinder, two-stroke aircraft engine, that was built by BRP-Rotax GmbH & Co. KG of Austria for use in ultralight aircraft.Raisner, William: ''LEAF catlog'', pages 6-105. Leading Edge Airfoils, 1995. Development The ...

. Production of the engine was completed in the late 1980s and today only used engines and parts are available.

Applications

Specifications (G-25B-1)

References

{{Zenoah aircraft engines Air-cooled aircraft piston engines Two-stroke aircraft piston engines