KTM 250 EXC EU User Manual

26 TECHNICAL DATA 208
26.1 Engine
26.1.1 All 250 models
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)
Bore 66.4 mm (2.614 in)
Exhaust valve - Beginning of adjustment 5,600 rpm
Exhaust valve - end of adjustment with red auxiliary spring 7,200 rpm
Exhaust valve - end of adjustment with yellow auxiliary spring 7,900 rpm
Exhaust valve - end of adjustment with green auxiliary spring 8,400 rpm
Crankshaft bearing 1 grooved ball bearing/1 roller bearing
Conrod bearing Needle bearing
Piston pin bearing Needle bearing
Pistons Aluminum cast
Piston rings 2 half keystone rings
X (upper edge of piston to upper edge of cylinder) 0… 0.10 mm (0… 0.0039 in)
Z (height of control flap) 48 mm (1.89 in)
Primary transmission 26:72
Clutch Multidisc clutch in oil bath/hydraulically activated
Gearbox 6-gear, claw shifted
Transmission ratio
1st gear 14:32
2nd gear 16:26
3rd gear 20:25
4th gear 22:23
5th gear 25:22
6th gear 26:20
Ignition Contactless controlled fully electronic ignition with digital igni-
tion adjustment, type Kokusan
Ignition point (BTDC) 1.9 mm (0.075 in)
Spark plug NGK BR 7 ES
Spark plug electrode gap 0.60 mm (0.0236 in)
Starting aid Kick starter and electric starter
26.1.2 All 300 models
Design 1-cylinder 2-stroke engine, water-cooled, with reed intake and
exhaust control
Displacement 293 cm³ (17.88 cu in)
Stroke 72 mm (2.83 in)
Bore 72 mm (2.83 in)
Exhaust valve - Beginning of adjustment 5,600 rpm
Exhaust valve - end of adjustment with red auxiliary spring 7,200 rpm
Exhaust valve - end of adjustment with yellow auxiliary spring 7,900 rpm
Exhaust valve - end of adjustment with green auxiliary spring 8,400 rpm
Crankshaft bearing 1 grooved ball bearing/1 roller bearing
Conrod bearing Needle bearing
Piston pin bearing Needle bearing
Pistons Aluminum cast
Piston rings 2 rectangular rings
X (upper edge of piston to upper edge of cylinder) 0… 0.10 mm (0… 0.0039 in)
Z (height of control flap) 48.5 mm (1.909 in)

KTM 250 EXC EU Specifications

General

Transmission	6-speed
Ignition	Kokusan
Front Wheel	1.60 x 21"
Rear Wheel	2.15 x 18"
Seat Height	960 mm
Engine Type	2-stroke
Displacement	249 cm³
Bore x Stroke	66.4 mm x 72 mm
Cooling	Liquid-cooled
Front Suspension	WP Xplor 48, USD fork
Rear Suspension	WP XPLOR shock absorber with linkage
Front Brake	Disc brake
Rear Brake	Disc brake
Fuel Capacity	9 l