KTM 50 SX 2020, Owner'S Manual

Page: 125 / 141

TECHNICAL DATA 21
123
21.1 Engine
Design 1-cylinder 2-stroke engine, water-cooled, with reed
intake
Displacement 49.0 cm³ (2.99 cu in)
Stroke 40 mm (1.57 in)
Bore 39.5 mm (1.555 in)
Crankshaft bearing 2 grooved ball bearings
Conrod bearing Needle bearing
Piston pin bearing Needle bearing
Pistons Aluminum cast
Piston rings 1 rectangular ring
Engine lubrication (50 SX) Mixture oil lubrication
Engine lubrication (50 SX Mini) Separate lubrication
Primary transmission 33:61 straight cut spur gear
Clutch Multi-disc centrifugal force clutch on the main shaft
Gearbox Rigid 1-stage reduction gear
Transmission ratio 14:31
Ignition SELETTRA 2p D36
Spark plug NGK LR 8 B
Spark plug electrode gap 0.60 mm (0.0236 in)
Cooling Water-cooled
Starting aid Kick starter system
21.2 Engine tightening torques
Screw, bearing retainer M5 5 Nm (3.7 lbf ft)
Screw, kick starter lever M5 6 Nm (4.4 lbf ft)
Loctite ® 243™
Screw, oil pump (50 SX Mini) M5 6 Nm (4.4 lbf ft)
Screw, stator clamp M5 6 Nm (4.4 lbf ft)
Loctite ® 222™
Screw, water pump impeller M5 2 Nm (1.5 lbf ft)
Loctite ® 243™
Bleeder flange of engine case M6 4 Nm (3 lbf ft)
Loctite ® 243™
Drain plug, water pump cover M6 6 Nm (4.4 lbf ft)
Screw, alternator cover M6 6 Nm (4.4 lbf ft)
Screw, clutch cover M6 10 Nm (7.4 lbf ft)
Screw, engine case M6 10 Nm (7.4 lbf ft)
Screw, engine sprocket cover M6 10 Nm (7.4 lbf ft)
Screw, exhaust flange M6 10 Nm (7.4 lbf ft)
Loctite ® 243™
Screw, fitting pin M6 10 Nm (7.4 lbf ft)
Loctite ® 2701™
Screw, gear oil level monitoring M6 6 Nm (4.4 lbf ft)
Screw, ground wire M6 6 Nm (4.4 lbf ft)