KTM 250 SX 2010 User Manual

TROUBLESHOOTING 73
Faults Possible cause Action
Engine overheats Radiator fins very dirty – Clean the radiator fins.
Foam formation in cooling system –
Drain the coolant. x ( p. 59)
–
Refill with coolant. x ( p. 60)
Damaged cylinder head or cylinder
head gasket
– Check the cylinder head or cylinder head gas-
ket.
Bent radiator hose –
Change the radiator hose. x
Incorrect ignition point due to loose
stator
–
Adjust the ignition. x
White smoke emission (steam in
exhaust gas)
Damaged cylinder head or cylinder
head gasket
– Check the cylinder head or cylinder head gas-
ket.
Gear oil exits at the vent hose Too much gear oil added – Check the gear oil level. ( p. 68)
Water in the gear oil Damaged shaft seal ring or water
pump
– Check the shaft seal ring and water pump.

KTM 250 SX 2010 Specifications

General

Displacement	249 cc
Bore x Stroke	66.4 mm x 72 mm
Cooling System	Liquid-cooled
Transmission	5-speed
Rear Suspension	WP Monoshock
Front Brake	Single Disc, 260 mm
Rear Brake	Single Disc, 220 mm
Seat Height	992 mm
Ground Clearance	385 mm
Fuel System	Carburetor
Ignition	Kokusan
Starter	Kickstarter
Front Tire	80/100-21
Rear Tire	110/90-19
Wheelbase	1475 mm
Engine Type	Single Cylinder, 2-Stroke
Front Suspension	WP USD Fork, 48 mm
Fuel Capacity	7.5 liters