KTM 125 SX 2021 User Manual

SERVICE WORK ON THE CHASSIS 11
71
K01197-10
Main work
– Pull the chain at the end of the chain sliding piece upward to
measure chain tension
A
.
Guideline
Lower chain section
1
must be taut.
Info
Chain wear is not always even, so you should repeat
this measurement at different chain positions.
Chain tension 55 … 58 mm (2.17 …
2.28 in)
» If the chain tension does not meet the specification:
– Adjust the chain tension. ( p. 71)
Finishing work
– Remove the motorcycle from the lift stand. ( p. 49)
11.36 Adjusting the chain tension
Warning
Danger of accidents Incorrect chain tension damages components and results in accidents.
If the chain is tensioned too much, the chain, engine sprocket, rear sprocket, transmission and rear
wheel bearings wear more quickly. Some components may break if overloaded.
If the chain is too loose, the chain may fall off the engine sprocket or the rear sprocket. As a result, the
rear wheel locks or the engine will be damaged.
– Check the chain tension regularly.
– Set the chain tension in accordance with the specification.
Preparatory work
– Raise the motorcycle with a lift stand. ( p. 49)
– Check the chain tension. ( p. 70)

KTM 125 SX 2021 Specifications

General

Engine Type	1-cylinder, 2-stroke engine
Displacement	124.8 cm³
Bore x Stroke	54 mm x 54.5 mm
Starter	Kickstarter
Transmission	6-speed
Front Suspension	WP XACT-USD, Ø 48 mm
Rear Suspension	WP XACT Monoshock with linkage
Cooling	Liquid cooled
Front Tire	80/100-21"
Rear Tire	100/90-19"
Seat Height	950 mm
Ground Clearance	375 mm
Frame	Central tube frame made of chrome molybdenum steel
Front Brake	Disc brake
Rear Brake	Disc brake
Fuel Tank Capacity	7.5 liters
Fuel System	Mikuni TMX carburetor