The Rotax 503 is a , inline 2-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 ...
aircraft engine, 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.]
As of 2011 the Rotax 503 is no longer in production.
Design and development
The Rotax 503 is piston ported with air-cooled cylinders and heads, utilizing either an engine driven fan and cowl, or free air cooling. Lubrication is either by use of pre-mixed fuel and oil or oil injection from an externally mounted oil tank. The 503 has dual independent breakerless, magneto capacitor-discharge ignition (CDI) systems. It can be equipped with either one or two piston-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 ...
s. It uses a manifold-driven pneumatic fuel pump to provide fuel pressure. An optional High Altitude Compensation kit is available.
The engine's propeller drive is via a Rotax type B, C, or E style gearbox. The standard engine includes a muffler exhaust system with an extra after-muffler as optional. The standard starter is a
recoil start
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 ...
type, with an electric starter optional. An integral
alternating current
Alternating current (AC) is an electric current which periodically reverses direction and changes its magnitude continuously with time in contrast to direct current (DC) which flows only in one direction. Alternating current is the form in whic ...
generator producing 170 watts at 12 volts with external rectifier-regulator is optional. The engine includes an intake air filter and can be fitted with an intake silencer system.
Limitations
The manufacturer acknowledges the design limitations of this engine, warning pilots:
Applications
Specifications (503)
References
External links
{{Rotax aeroengines
Air-cooled aircraft piston engines
Rotax engines
Two-stroke aircraft piston engines