503 UL

SKYDRIVE Limited. UK Distributor for ROTAX Aircraft Engines

ROTAX Ž is the
registered trademark of
Bombardier-Rotax GmbH.

503 UL

2 cylinder, 2-stroke engine with dual electronic ignition. Comes complete with carb(s), exhaust system, rewind starter and fuel pump.

46 hp, fan or free air cooled, single carb ŁPOA
50 hp, fan or free air cooled, twin carb ŁPOA

Oil Injection is available for 503 engines (this means that you do not need to mix your oil and petrol before putting it in to your fuel tank - you just put neat fuel in your tank and oil in a separate reservoir). Telephone for price and further details.

Version	Performance			Torque			Max rpm
Version	kW	hp	1/min	Nm	ft. lb.	1/min	1/min
503 UL-1V	34.0	45.6	6500	51	37.6	5900	6800
503 UL-2V	37.0	49.6	6500	56	41.3	6000	6800

Bore		Stroke		Displacement		Compression ratio
72 mm	2.84 in	61 mm	2.40 in	496.7 cm³	30.31 cu.in	th:10.8	ef: 6.2

Fuel	Super 2-stroke motoroil	Mixing Ratio
min. MON 83 RON 91 min. AKI 87 leaded or unleaded	API TC- Classification	1:50 (variable with fresh oil pump)

Ignition Unit	Ignition Timing	Spark Plug
DUCATI single CDI	16° v.OT	ROTAX part number 897 055

Generator Performance	R.P.M.	Voltage
155 W DC	6000 1/min	13.5 V

Diagrams and specifications shown here are for the Fan cooled D.C.D.I variant of the 503UL. Free air cooled and single carb versions also available.

! Warning !

This aircraft engine does not comply with federal safety regulations for standard aircraft. This engine is for use in experimental and ultralight uncertified aircraft only and only in circumstances in which an engine failure will not compromise safety. Before operating the engine read operators manual. Information is available from your local authorised ROTAX distributor.

Weight		kg	lb
standard	engine	31.4	69.2
	2 carburetors	1.8	4.0
	exhaust system	5.1	11.2
options	2 air cleaners	0.3	0.7
	dual air cleaner	0.5	1.1
	electric starter	3.5	7.7
	gearbox B / i = 2.0/2.24/2.58	4.5	9.9
	gearbox C / i = 2.62/3.0/3.47/4.0	8.0	17.6
	gearbox E / i = 2.62/3.0/3.47/4.0	11.2	24.7
	external alternator 220 W DC	1.1	2.4
	oil tank 2.4 L	1.2	3.5
	fresh oil pump	0.3	0.7
	HAC kit	0.2	0.4
	intake silencer 1V	0.8	1.8
	intake silencer 2V	1.1	2.4
	after muffler	1.6	3.5