What is the proper plug gap?

[david holmes]

Rotax 503
NGK R BR8ES

[scottessex]

Here ya go, and afew other tidbits of info!

Rotax 503 Specifications DESCRIPTION: Two-cycle, two-cylinder engine, oil in fuel lubrication
BORE: 72.0mm (2.835 in.)
STROKE: 61mm (2.40 in.)
DIRECTION OF ROTATION: Counter- clockwise, viewed towards PTO (without reduction gear box)
DISPLACEMENT: 496.7 c.c. (30.31 cu. in.)
COMPRESSION RATIO: Theoretical 10.8 - effective 6.2
POWER OUTPUT: 34.0 kw (46 hp) configuration single carb.
MAXIMUM RPM: 6800 rpm.
DIRECTION OF ROTATION: Counter- clockwise, viewed towards PTO (without reduction gear box)
CYLINDER: 2 light alloy cylinders with cast iron sleeves
PISTON: Aluminum cast piston with 2 rings
PISTON/CYLINDER CLEARANCE: 0.07 - 0.08mm (.0028 - .0032 in.)
IGNITION SYSTEM: Breakerless Ducati capacitor discharge dual ignition with magneto generator.
GENERATOR OUTPUT: 170 W AC at 6000 rpm and 13.5 V RMS
RECTIFIER- REGULATOR: (optional) a.) #9103 requires min. load 12 W (1 amp) to regulate
b.) #9251 requires no min. load
IGNITION TIMING: 1.47mm = .059 in. (16 degrees B.T.D.C.)
SPARK PLUG: 14 mm NGK B8ES
ELECTRODE GAP: .015 in.
CARBURETOR: 1 x BING 36mm (1.42 in.) hand lever choke
FUEL PUMP: pneumatic fuel pump #6903 for single carb
FUEL: Regular or premium gasoline, octane not lower than 90 octane (unleaded fuels)
LUBRICATION OF ENGINE: Super 2- stroke oil (AV-2), proposed ASTM/CEC
STARTER: Rewind starter - standard
(optional) electric starter, magneto side without rewind starter
REDUCTION GEARBOX "B":
(optional) Reduction gear box with torsional shock absorber, for propeller interia up to 3000 kg cm sq.
REDUCTION GEAR BOX "C":
(optional) Reduction gear box with torsional shock absorber, for propeller interia up to 6000 kg cm sq.
RATIOS: 2.62 to 1, 3.00 to 1, 3.47 to 1, 4.00 to 1.
LUBRICATION OF GEAR BOX: Gear oil, GL5 or GL6, SAE 140EP, or 85 W-140 EP
DIRECTION OF PROP SHAFT ROTATION: Clockwise, viewed towards propeller flange.
COOLING: Air cooled by axial fan
WEIGHT: Engine wo/: carburetor, air filter, fuel pump, exhaust system............................................ .......67.0 lbs.......(30.4 kg )
2 carbs w/ sockets...................................4.0 lbs........(1.8 kg )
exhaust system assy...............................10.8 lbs........(4.9 kg )
2 air filter............................................ .....0.6 lbs........(0.3 kg )
electric start kit, mag end.1.......................7.7 lbs........(3.5 kg)
start kit, mag end.1...................................7.7 lbs........(3.5 kg )
Reduction box "B"....................................9.9 lbs........(4.5 kg )
Reduction box "C"..................................16.3 lbs........(8.1 kg )

OPTIONS:

[Harry_S.]

David;

Ask and ye shall get.


Cheers