KTM 50 SX PRO JUNIOR LC 2003, Owner'S Manual

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TECHNICAL DATA – ENGINE 50 LC 2003
Engine 50 SX PRO JUNIOR LC 50 SX PRO SENIOR LC
Design single cylinder 2-stroke engine, with reed valve inlet
Displacement 49.0 ccm
Bore/Stroke 39.5 / 40 mm
Fuel SUPER fuel, research octane no 95, mixed with 2-stroke oil
Oil/gasoline ratio 1 : 40 when using high grade 2-stroke oil (Shell Advance Racing X)
When in doubt, please contact your importer or use 1 : 33 mix ratio to be on the safe side
Lubrication mixture lubrication
Crankshaft bearing 2 grooved ball bearing
Connecting rod bearing needle bearing
Piston pin bearing needle bearing
Piston rings 1 rectangular ring
Primary drive straight cut spur gears, 16 : 57 Z
Transmission oil 0.15-0,2 liter automatic gear oil Dexron II (Shell Donax TA)
Spark plug NGK BR 8 ECM
Electrode gap 0.6 mm
Carburetor DellOrto PHVA 14 DS Dell’Orto PHBG 19 BS
Air filter wet foam type air filter insert
Cooling liquid 0.5 litres, 40% antifreeze, 60% water, at least -25 °C (-13 °F)
Primary gear nut M14x1,25 40 Nm
Hexagon nut ignition rotor M10x1,25 20 Nm
Nut of clutch hub M10x1,25 Loctite 243 + 35 Nm
Cylinder head screws M7 15 Nm
Cylinder base nuts M8 18 Nm
Allan head screw-Stator M5x25 Loctite 243 + 8 Nm
Oil plug M16 5 Nm
Oil drain plug M10 15 Nm
Other engine screws M5 7 Nm
M6 10 Nm
M8 30 Nm
TIGHTENING TORQUES - ENGINE
Model 50 SX PRO JUNIOR LC 50 SX PRO SENIOR LC
Type Dell’Orto PHVA 14 DS Dell’Orto PHBG 19 BS
Main jet 80 85
Needle jet 211 FA 260 AU
Idling jet 45 48
Jet needle A10 W9
Needle position from top 3. 3.
Air/Mixture reg. screw open 3.5 3.0
Slide 40 60
Starting jet 60 60
BASIC CARBURETOR SETTING