KTM 250 SX 2021 - Carburetor

TECHNICAL DATA 20
117
20.1 Engine
Design 1-cylinder 2-stroke engine, water-cooled, with reed
intake and exhaust control
Displacement 249 cm³ (15.19 cu in)
Stroke 72 mm (2.83 in)
Hole 66.4 mm (2.614 in)
Exhaust control - setting measurement 1.8
+ 0.2
− 0
mm (0.071
+ 0.008
− 0
in)
Crankshaft bearing 1 grooved ball bearing/1 roller bearing
Conrod bearing Needle bearing
Piston pin bearing Needle bearing
Piston Cast aluminum
Piston rings 2 half keystone rings
X distance (upper edge of piston to upper edge of
cylinder)
0 … 0.10 mm (0 … 0.0039 in)
Z distance (height of control flap) 49.0 mm (1.929 in)
Primary transmission 26:73
Clutch Multidisc clutch in oil bath/hydraulically activated
Transmission 5-gear transmission, claw shifted
Transmission ratio
first-gear 14:28
second-gear 16:26
third-gear 18:24
fourth-gear 21:24
fifth-gear 22:21
Ignition system Contactless controlled fully electronic ignition with
digital ignition adjustment
Spark plug NGK BR 8 ECM
Spark plug electrode gap 0.60 mm (0.0236 in)
Starting aid Kick starter system
20.2 Engine tightening torques
Screw, inner membrane sheets EJOTDELTA PT
®
35x25 1 Nm (0.7 lbf ft)
Screw, membrane support plate EJOTDELTA PT
®
30x12 1 Nm (0.7 lbf ft)
Screw, outer membrane sheets EJOTDELTA PT
®
30x6 1 Nm (0.7 lbf ft)
Screw, angle lever, exhaust control M5 6 Nm (4.4 lbf ft)
Loctite
®
243™
Screw, bearing retainer M5 6 Nm (4.4 lbf ft)
Loctite
®
243™
Screw, clutch spring retainer M5 6 Nm (4.4 lbf ft)
Screw, crankshaft speed sensor M5 6 Nm (4.4 lbf ft)
Loctite
®
243™
Screw, exhaust control bearing
support
M5 6 Nm (4.4 lbf ft)
Loctite
®
243™
Screw, exhaust control cap M5 5 Nm (3.7 lbf ft)
Screw, exhaust control cover M5 4 Nm (3 lbf ft)