KTM 250 SX, 150 SX User Manual

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OWNER'S MANUAL 2010

125 SX 150 SX 250 SX

Art. no. 3211480en

DEAR KTM CUSTOMER 1

DEARKTM CUSTOMER

Congratulations on your decision to purchase a KTM motorcycle. You are now the owner of a state-of-the-art sports motorcycle that will give you enormous pleasure if you service and maintain it accordingly.

We wish you great pleasure riding the vehicle!

Enter the serial numbers of your vehicle below.

Chassis number ( p. 9) Dealer's stamp

Engine number ( p. 9)

The owner's manual corresponded to the latest state of this series at the time of printing. Slight deviations resulting from continuing development and design can, however, not be completely excluded.

All specifications are non-binding. KTM Sportmotorcycle AG specifically reserves the right to modify or delete technical specifications, prices, colors, forms, materials, services, designs, equipment, etc., without prior notice and without specifying reasons, to adapt these to local conditions, as well as to stop production of a particular model without prior notice. KTM accepts no liability for delivery options, deviations from illustrations and descriptions, as well as misprints and other errors. The models portrayed partly contain special equipment that does not belong to the regular scope of delivery.

ISO 9001(12 100 6061) According to the international quality management standard ISO 9001, KTM uses quality assurance processes that lead to the maximum possible quality of the products. Issued by: TÜV Management Service

KTM-Sportmotorcycle AG 5230 Mattighofen, Austria

TABLE OF CONTENTS 2

TABLEOF CONTENTS

MEANS OF REPRESENTATION ............................................ 4

IMPORTANT INFORMATION ................................................ 5

VIEW OF VEHICLE............................................................... 7

View of the vehicle from the left front (example) ................. 7

View of the vehicle from the right rear (example) ................ 8

LOCATION OF SERIAL NUMBERS ........................................ 9

Chassis number............................................................... 9

Type label....................................................................... 9

Engine number................................................................ 9

Fork part number............................................................. 9

Shock absorber part number ............................................. 9

CONTROLS....................................................................... 10

Clutch lever .................................................................. 10

Hand brake lever ........................................................... 10

Short circuit button ....................................................... 10

Throttle grip.................................................................. 10

Fuel tap........................................................................ 11

Opening the filler cap .................................................... 11

Closing the filler cap...................................................... 11

Choke........................................................................... 11

Shift lever..................................................................... 12

Kickstarter.................................................................... 12

Foot brake lever............................................................. 12

Plug-in stand ................................................................ 13

GENERAL TIPS AND HINTS ON PUTTING INTO

OPERATION...................................................................... 14

Advice on first use ......................................................... 14

Running in the engine.................................................... 15

Preparing the vehicle for difficult operating conditions...... 15

Preparations for riding on dry sand.................................. 15

Preparations for riding on wet sand ................................. 16

Preparations for riding on wet and muddy surfaces ........... 17

Preparations for riding at high temperatures and riding

slowly........................................................................... 18

Preparations for riding at low temperatures and in snow .... 18

RIDING INSTRUCTIONS .................................................... 19

Checks before putting into operation ............................... 19

Starting ........................................................................ 19

Starting up ................................................................... 20

Shifting, riding.............................................................. 20

Braking ........................................................................ 20

Stopping, parking .......................................................... 21

Refueling...................................................................... 21

SERVICE SCHEDULE......................................................... 23

Important maintenance work that must be done in an

authorized KTM workshop .............................................. 23

Important maintenance work to be carried out by an

authorized KTM workshop (as additional order)................. 24

Important checks and maintenance work to be carried

out by the rider ............................................................. 24

MAINTENANCE WORK ON CHASSIS AND ENGINE .............. 26

Jacking up the motorcycle .............................................. 26

Removing the motorcycle from the work stand.................. 26

Checking the basic chassis setting with the rider's

weight .......................................................................... 26

Compression damping of shock absorber.......................... 26

Adjusting the high-speed compression damping of the

shock absorber .............................................................. 26

Adjusting the low-speed compression damping of the

shock absorber .............................................................. 27

Adjusting the rebound damping of the shock absorber....... 28

Measuring the sag of the unloaded rear wheel .................. 28

Checking the static sag of the shock absorber .................. 29

Checking the riding sag of the shock absorber .................. 29

Adjusting the spring preload of the shock absorber x ...... 29

Adjusting the riding sag x............................................. 30

Removing the shock absorber x..................................... 30

Installing the shock absorber x ..................................... 31

Checking the basic setting of the fork.............................. 31

Adjusting the compression damping of the fork ................ 31

Adjusting the rebound damping of the fork....................... 32

Bleeding the fork legs .................................................... 32

Cleaning the dust boots of the fork legs ........................... 32

Loosening the fork protection.......................................... 33

Positioning the fork protection ........................................ 33

Checking the play of the steering head bearing................. 33

Adjusting the play of the steering head bearing x............ 34

Removing the fork legs x.............................................. 34

Installing the fork legs x............................................... 35

Removing the fork protector x....................................... 35

Installing the fork protector x ....................................... 35

Removing the lower triple clamp x ................................ 36

Installing the lower triple clamp x................................. 36

Greasing the steering head bearing x............................. 37

Removing the front fender .............................................. 37

Installing the front fender............................................... 37

Removing the start number plate .................................... 37

Installing the start number plate ..................................... 38

Handlebar position ........................................................ 38

Adjusting the handlebar position x................................ 38

Checking the play in the throttle cable............................. 39

Adjusting the play in the throttle cable x ....................... 39

Checking the chain for dirt ............................................. 39

Cleaning the chain......................................................... 39

Checking the chain tension ............................................ 40

Checking the rear sprocket/engine sprocket for wear ......... 40

Checking chain wear...................................................... 40

Adjusting the chain tension ............................................ 41

Adjusting the chain guide x.......................................... 42

Checking the brake discs................................................ 42

Checking the free travel of the hand brake lever ............... 43

Adjusting the basic position of the hand brake lever.......... 43

Checking the front brake fluid level ................................. 43

Adding front brake fluid x ............................................ 44

Checking the front brake linings...................................... 44

Removing the front brake linings x................................ 45

Installing the front brake linings x................................. 45

Changing the front brake linings x................................. 46

Checking the free play of the foot brake lever ................... 46

Adjusting the basic position of the foot brake lever x ...... 47

Checking the rear brake fluid level .................................. 47

Adding rear brake fluid x.............................................. 48

Checking the rear brake linings ....................................... 48

Removing the rear brake linings x ................................. 49

Installing the rear brake linings x.................................. 49

Changing the rear brake linings x.................................. 50

Removing the front wheel x .......................................... 50

Installing the front wheel x........................................... 51

Removing the rear wheel x ........................................... 52

Installing the rear wheel x ............................................ 52

Checking the tire condition............................................. 53

Checking the tire air pressure ......................................... 54

Checking the spoke tension ............................................ 54

TABLE OF CONTENTS 3

Ignition curve plug connection ........................................ 54

Changing the ignition curve ............................................ 55

Engine characteristic - auxiliary spring (250 SX)............... 55

Engine characteristic - adjusting the auxiliary spring x

(250 SX) ...................................................................... 55

Removing the seat ......................................................... 56

Mounting the seat ......................................................... 56

Removing the fuel tank x ............................................. 56

Installing the fuel tank x .............................................. 57

Cooling system .............................................................. 58

Checking the antifreeze and coolant level ........................ 58

Checking the coolant level.............................................. 59

Draining the coolant x.................................................. 59

Refilling with coolant x ................................................ 60

Removing the main silencer............................................ 61

Installing the main silencer ............................................ 61

Glass fiber yarn filling of main silencer ............................ 61

Changing the glass fiber yarn filling of the main

silencer x ................................................................... 61

Removing the glass fiber yarn filling of the main

silencer x ................................................................... 62

Installing the glass fiber yarn filling of the main

silencer x ................................................................... 62

Removing the air filter box lid......................................... 62

Installing the air filter box lid.......................................... 62

Removing the air filter x............................................... 63

Installing the air filter x ............................................... 63

Cleaning the air filter x ................................................ 63

Adjusting the basic position of the clutch lever................. 64

Checking the fluid level of the hydraulic clutch ................ 64

Changing the hydraulic clutch fluid x ............................ 65

Checking the basic position of the shift lever.................... 66

Adjusting the basic position of the shift lever x .............. 66

Carburetor .................................................................... 66

Carburetor - adjusting the idle speed x .......................... 67

Emptying the carburetor float chamber x ....................... 68

Checking the gear oil level.............................................. 68

Changing the gear oil x ................................................ 69

Draining the gear oil x ................................................. 69

Refilling with gear oil x ................................................ 70

Adding gear oil x ......................................................... 70

TROUBLESHOOTING......................................................... 72

CLEANING........................................................................ 74

Cleaning the motorcycle ................................................. 74

STORAGE ......................................................................... 75

Storage......................................................................... 75

Putting into operation after storage ................................. 75

TECHNICAL DATA - ENGINE .............................................. 76

125 SX......................................................................... 76

150 SX......................................................................... 76

250 SX......................................................................... 77

Capacity - gear oil.......................................................... 77

Capacity - coolant.......................................................... 77

TECHNICAL DATA - ENGINE TIGHTENING TORQUES .......... 78

125 SX, 150 SX............................................................ 78

250 SX......................................................................... 78

TECHNICAL DATA - CARBURETOR..................................... 80

125 SX......................................................................... 80

Carburetor - basic setting for sandy surfaces (125 SX) ...... 80

Carburetor configuration (125 SX)................................... 81

150 SX......................................................................... 82

Carburetor - basic setting for sandy surfaces (150 SX) ...... 82

Carburetor configuration (150 SX)................................... 83

250 SX......................................................................... 84

Carburetor - basic setting for sandy surfaces (250 SX) ...... 84

Carburetor configuration (250 SX)................................... 85

TECHNICAL DATA - CHASSIS ............................................ 86

Tires ............................................................................ 86

Capacity - fuel............................................................... 86

TECHNICAL DATA - FORK.................................................. 87

125 SX, 150 SX............................................................ 87

250 SX......................................................................... 87

TECHNICAL DATA - SHOCK ABSORBER ............................. 88

125 SX, 150 SX............................................................ 88

250 SX......................................................................... 88

TECHNICAL DATA - TIGHTENING TORQUES FOR

CHASSIS .......................................................................... 90

WIRING DIAGRAM ............................................................ 92

Wiring diagram.............................................................. 92

SUBSTANCES................................................................... 94

AUXILIARY SUBSTANCES.................................................. 96

STANDARDS..................................................................... 98

INDEX .............................................................................. 99

MEANS OF REPRESENTATION 4

Symbols used

The symbols used are explained below.

Indicates an expected reaction (e.g. of a work step or a function).

Indicates an unexpected reaction (e.g. of a work step or a function).

All work marked with this symbol requires specialist knowledge and technical understanding. In the interest of your own safety, have these jobs done in an authorized KTM workshop! There, your motorcycle will be serviced optimally by specially trained experts using the specialist tools required.

Identifies a page reference (more information is provided on the specified page).

Formats used

The typographical and other formats used are explained below.

Specific name Identifies a specific name.

Name

Brand™ Identifies a brand available on the open market.

Identifies a protected name.

IMPORTANT INFORMATION 5

Use definition

KTM sport motorcycles are designed and built to withstand the normal stresses and strains of competitive use. The motorcycles comply with currently valid regulations and categories of the top international motorsport organizations.

Info

The motorcycle must be used only in closed off areas remote from public road traffic.

Maintenance

A prerequisite for perfect operation and prevention of wear is that the engine and chassis maintenance and adjustment work described in the owner's manual are properly carried out. Poor adjustment and tuning of the engine and chassis can lead to damage and breakage of components. Using the motorcycle in difficult conditions such as on sand or very muddy or wet terrain can lead to above-average wear of components such as the transmission train or the brakes. For this reason, it may be necessary to service or replace worn parts before the limit specified in the service schedule is reached. Pay careful attention to the prescribed running-in period, inspection and maintenance intervals. If you observe these exactly, you will ensure a much longer service life for your motorcycle.

Warranty

The work prescribed in the service schedule must be carried out in an authorized KTM workshop only and confirmed in the customer's service record, since otherwise no warranty claims will be honored. No warranty claims can be considered for damage resulting from manipulations and/or alterations to the vehicle.

Fuel, oils, etc.

You should use the fuels, oils and greases according to specifications as listed in the owner's manual.

Spare parts, accessories

For your own safety, only use spare parts and accessory products that have been approved and/or recommended by KTM and have them installed by an authorized KTM workshop. KTM accepts no liability for other products and any resulting damage or loss. Certain spare parts and accessories are specified in parentheses in the descriptions. Your KTM dealer will be glad to advise you.

You will find the current KTM PowerParts for your vehicle on the KTM website. International KTM Website: http://www.ktm.com

Work rules

Special tools are needed for certain tasks. They are not included with the vehicle but can be ordered under the number in parentheses. E.g.: bearing puller (15112017000) When the vehicle is assembled, non-reusable parts (e.g., self-locking screws and nuts, gaskets, seal rings, O-rings, splints, lock washers) must be replaced with new parts. Where thread lockers are used on screw connections (e.g., Loctite®), follow the instructions for use from the manufacturer. After disassembly, clean the parts that are to be reused and check them for damage and wear. Replace damaged or worn parts. After you complete the repair or maintenance work, check the roadworthiness of the vehicle.

Transport

Note

Danger of damage The parked vehicle can roll away or fall over.

– Always place the vehicle on a firm and even surface.

Note

Fire hazard Some vehicle components become very hot when the vehicle is operated.

– Do not park the vehicle near flammable or explosive substances. Do not place objects on the vehicle while it is still warm from

being run. Always let the vehicle cool first.

– Switch off the engine. – Turn handle  of the fuel tap to the OFF position. (Figure B00003-10 p. 11) – Use straps or other suitable devices to secure the motorcycle against accidents or falling over.

IMPORTANT INFORMATION 6

Environment

Motorcycling is a wonderful sport and we naturally hope that you can enjoy it to the full. However, it is a potential problem for the environment and can lead to conflicts with other persons. But if you use your motorcycle responsibly, you can ensure that such problems and conflicts do not have to occur. To protect the future of motorcycle sport, make sure that you use your motorcycle legally, display environmental consciousness, and respect the rights of others.

Notes/warnings

Pay close attention to the notes/warnings.

Info

Various information and warning labels are affixed to the vehicle. Do not remove information/warning labels. If they are missing, you or others may not recognize potential hazards and may therefore be injured.

Grades of risks

Danger

Identifies a danger that will immediately and invariably lead to fatal or serious permanent injury if the appropriate measures are not taken.

Warning

Identifies a danger that is likely to lead to fatal or serious injury if the appropriate measures are not taken.

Note

Identifies a danger that will lead to considerable machine and material damage if the appropriate measures are not taken.

Warning

Identifies a danger that will lead to environmental damage if the appropriate measures are not taken.

Owner's manual

– It is important that you read this owner's manual carefully and completely before making your first trip. It contains information and

tips that will assist you in operating and handling your motorcycle properly. Only then will you learn how to adjust the motorcycle to your own requirements and how to protect yourself from injury. The owner's manual also contains important information on servicing the motorcycle.

– The owner's manual is an important component of the motorcycle and should be handed over to the new owner if the vehicle is

sold.

VIEW OF VEHICLE 7

3.1View of the vehicle from the left front (example)

1 Hand brake lever 2 Short circuit button 3 Clutch lever 4 Air filter box lid 5 Fuel tap 6 Choke button 7 Shift lever 8 Chain guide

B00010-10

VIEW OF VEHICLE 8

3.2View of the vehicle from the right rear (example)

1 Shock absorber rebound adjustment 2 Level viewer for brake fluid, rear 3 Fork rebound adjustment 4 Foot brake lever 5 Kickstarter 6 Shock absorber compression adjustment 7 Throttle grip 8 Fork compression adjustment 9 Filler cap

B00014-10

LOCATION OF SERIAL NUMBERS 9

4.1Chassis number

The chassis number  is stamped on the right side of the steering head.

B00015-10

4.2Type label

The type label  is fixed to the front of the steering head.

4.3Engine number

4.4Fork part number

400284-10

The engine number  is stamped on the left side of the engine under the engine sprocket.

B00016-10

The fork part number  is stamped on the inner side of the fork stub.

4.5Shock absorber part number

500082-10

The shock absorber part number  is stamped on the top of the shock absorber above the adjusting ring on the engine side.

500083-10

CONTROLS 10

5.1Clutch lever

(125 SX, 150 SX)

The clutch lever  is fitted on the left side of the handlebar. The clutch is hydraulically operated and self-adjusting.

B00001-10

(250 SX)

The clutch lever  is fitted on the left side of the handlebar. The clutch is hydraulically operated and self-adjusting.

B00009-10

5.2Hand brake lever

5.3Short circuit button

Hand brake lever  is located on the right side of the handlebar. The hand brake lever is used to activate the front brake.

400196-10

Short circuit button  is fitted on the left side of the handlebar.

Possible states

• Short circuit button in basic position – In this position, the ignition circuit is closed, and the engine can be started.

• Short circuit button pressed – In this position, the ignition circuit is interrupted, a running engine stops, and a non-running engine will not start.

B00002-10

5.4Throttle grip

Throttle grip  is fitted on the right side of the handlebar.

B00060-10

CONTROLS 11

5.5Fuel tap

The fuel tap is on the left side of the fuel tank. With tap handle  on the fuel tap, you can open or close the supply of fuel to the carburetor.

Possible states

• Fuel supply closed OFF – No fuel can flow from the tank to the carburetor.

• Fuel supply open ON – Fuel can flow from the tank to the carburetor. The fuel tank empties completely.

B00003-10

5.6Opening the filler cap

5.7Closing the filler cap

– Press release button , turn the filler cap counterclockwise and lift it free.

400199-10

– Replace the filler cap and turn clockwise until the release button  locks in place.

Info

Run the fuel tank breather hose  without kinks.

400199-11

5.8Choke

B00004-10

The choke  is fitted on the left side of the carburetor. Activating the choke function frees an opening through which the engine can draw extra fuel. This gives a richer fuel-air mixture, which is needed for a cold start.

Info

If the engine is warm, the choke function must be deactivated.

Possible states

• Choke function activated – The choke lever is pulled out to the stop.

• Choke function deactivated – The choke lever is pushed in to the stop.

CONTROLS 12

5.9Shift lever

Shift lever  is mounted on the left side of the engine.

B00005-10

(125 SX, 150 SX)

The gear positions can be seen in the photograph. The neutral or idle position is between the first and second gears.

B00005-12

(250 SX)

The gear positions can be seen in the photograph. The neutral or idle position is between the first and second gears.

5.10Kickstarter

5.11Foot brake lever

B00005-11

The kickstarter  is fitted on the right side of the engine. The top part can be swiveled.

B00006-10

Foot brake lever  is located in front of the right footrest. The foot brake lever is used to activate the rear brake.

B00007-10

CONTROLS 13

5.12Plug-in stand

Note

Danger of damage The parked vehicle can roll away or fall over.

– Always place the vehicle on a firm and even surface.

To park the motorcycle, insert plug-in stand  into the left side of the wheel spindle.

Info

400203-10

Remove the plug-in stand before riding.

GENERAL TIPS AND HINTS ON PUTTING INTO OPERATION 14

6.1Advice on first use

Danger

Danger of accidents Danger arising from the rider's judgement being impaired.

– Do not use the vehicle if you are inexperienced or if you have consumed alcohol or drugs.

Warning

Risk of injury Missing or poor protective clothing present an increased safety risk.

– Wear protective clothing (helmet, boots, gloves, pants and jacket with protectors) every time you ride the vehicle. Always

wear protective clothing, which must be undamaged and meet legal requirements.

Warning

Danger of crashing Poor vehicle handling due to different tire tread patterns on front and rear wheels.

– The front and rear wheels must be fitted with tires with similar tread patterns to prevent loss of control over the vehicle.

Warning

Danger of accidents Critical handling characteristic due to inappropriate riding style.

– Adapt your riding speed to the road conditoins and your riding ability.

Warning

Danger of accidents Accident risk caused by presence of a passenger.

– Your vehicle is not designed to carry passengers. Do not ride with a passenger.

Warning

Danger of accidents Failure of brake system.

– If the foot brake lever is not released, the brake linings drag permanently. The rear brake can fail due to overheating. Take

your foot off the foot brake lever if you do not want to brake.

Warning

Danger of accidents Unstable riding behavior.

– Do not exceed the maximum permissible weight and axle loads.

Warning

Risk of misappropriation Usage by unauthorized persons.

– Never leave the vehicle while the engine is running. Secure the vehicle against use by unauthorized persons.

Info

When using your motorcycle, remember that others may feel disturbed by excessive noise.

– Make sure that the pre-delivery inspection work has been carried out by an authorized KTM workshop.

You receive a delivery certificate and the service record at vehicle handover.

– Before your first trip, read the entire operating instructions carefully. – Get to know the controls. – Adjust the basic position of the clutch lever. ( p. 64) – Adjust the basic position of the hand brake lever. ( p. 43)

–

Adjust the basic position of the foot brake lever. x ( p. 47)

– Become accustomed to the handling of the motorcycle on suitable terrain.

Info

Your motorcycle is not authorized for riding on public roads. Offroad, you should be accompanied by another person on another machine so that you can help each other.

– Try also to ride as slowly as possible and in a standing position to get a better feeling for the vehicle. – Do not make any offroad trips that over-stress your ability and experience. – Hold the handlebar firmly with both hands and keep your feet on the footrests when riding. – Do not transport luggage. – Do not exceed the overall maximum permitted weight and the axle loads.

GENERAL TIPS AND HINTS ON PUTTING INTO OPERATION 15

Guideline

Maximum permissible overall weight 335 kg (739 lb.) Maximum permissible front axle load 145 kg (320 lb.) Maximum permissible rear axle load 190 kg (419 lb.)

– Check the spoke tension. ( p. 54)

Info

The spoke tension must be checked after riding the motorcycle for one half hour.

– Run the engine in.

6.2Running in the engine

– During the running-in phase, do not exceed the specified engine performance.

Guideline

Maximum engine performance

During the first 3 service hours < 70 % During the first 5 service hours < 100 %

– Avoid fully opening the throttle!

6.3Preparing the vehicle for difficult operating conditions

– The use of motorcycles under difficult operating conditions can lead to above-average wear of components such as the drive train

or brakes. For this reason, it may be necessary to service or replace worn parts before the limit specified in the service schedule is reached.

Difficult operating conditions are:

– Riding on dry sand. ( p. 15) – Riding on wet sand. ( p. 16) – Riding on wet and muddy surfaces. ( p. 17) – Riding at high temperatures and riding slowly. ( p. 18) – Riding at low temperatures and in snow. ( p. 18)

6.4Preparations for riding on dry sand

600872-10

– Check the radiator cap.

Value on radiator cap 1.8 bar (26 psi)

» If the value displayed does not meet specifications:

Warning

Danger of scalding During motorcycle operation, the coolant gets

very hot and is under pressure.

– Do not remove the radiator cap, radiator hoses or other cooling

system components when the engine is hot. Allow the engine and cooling system to cool down. In case of scalding, rinse immediately with lukewarm water.

– Change the radiator cap.

–

Seal the air filter box. x

Tip

Seal the air filter box at the edges to prevent dirt from entering.

–

Clean the air filter. x ( p. 63)

Info

Check the air filter approx. every 30 minutes.

GENERAL TIPS AND HINTS ON PUTTING INTO OPERATION 16

– Mount the dust cover for the air filter.

Dust cover for air filter (59006019000)

Info

Follow the KTM PowerParts mounting instructions.

600869-01

– Mount the sand cover for the air filter.

Sand cover for air filter (59006022000)

Info

Follow the KTM PowerParts mounting instructions.

– Adjust the carburetor jetting and setting.

600871-01

600868-01

6.5Preparations for riding on wet sand

600872-10

Info

The recommended carburetor tuning is available from your authorized KTM workshop.

– Clean the chain.

Chain cleaner ( p. 96)

– Mount the steel sprocket.

Tip

Do not lubricate the chain.

– Clean the radiator fins. – Carefully align bent radiator fins.

– Check the radiator cap.

Value on radiator cap 1.8 bar (26 psi)

» If the value displayed does not meet specifications:

Warning

Danger of scalding During motorcycle operation, the coolant gets

very hot and is under pressure.

– Do not remove the radiator cap, radiator hoses or other cooling

system components when the engine is hot. Allow the engine and cooling system to cool down. In case of scalding, rinse immediately with lukewarm water.

– Change the radiator cap.

–

Seal the air filter box. x

Tip

Seal the air filter box at the edges to prevent dirt from entering.

–

Clean the air filter. x ( p. 63)

Info

Check the air filter approx. every 30 minutes.

GENERAL TIPS AND HINTS ON PUTTING INTO OPERATION 17

– Mount the rain cover for the air filter.

Rain cover for air filter (59006021000)

Info

Follow the KTM PowerParts mounting instructions.

– Adjust the carburetor jetting and setting.

600870-01

– Clean the chain.

Chain cleaner ( p. 96)

– Mount the steel sprocket.

– Clean the radiator fins.

600868-01

6.6Preparations for riding on wet and muddy surfaces

– Carefully align bent radiator fins.

–

Seal the air filter box. x

–

Clean the air filter. x ( p. 63)

Info

The recommended carburetor tuning is available from your authorized KTM workshop.

Tip

Do not lubricate the chain.

Tip

Seal the air filter box at the edges to prevent dirt from entering.

Info

Check the air filter approx. every 30 minutes.

600870-01

600868-01

– Mount the rain cover for the air filter.

Rain cover for air filter (59006021000)

Info

Follow the KTM PowerParts mounting instructions.

– Adjust the carburetor jetting and setting.

Info

The recommended carburetor tuning is available from your authorized KTM workshop.

– Mount the steel sprocket. – Clean the motorcycle. ( p. 74) – Carefully align bent radiator fins.

GENERAL TIPS AND HINTS ON PUTTING INTO OPERATION 18

6.7Preparations for riding at high temperatures and riding slowly

– Check the radiator cap.

Value on radiator cap 1.8 bar (26 psi)

» If the value displayed does not meet specifications:

Warning

Danger of scalding During motorcycle operation, the coolant gets

very hot and is under pressure.

600872-10

– Change the radiator cap.

–

Seal the air filter box. x

–

Clean the air filter. x ( p. 63)

– Do not remove the radiator cap, radiator hoses or other cooling

system components when the engine is hot. Allow the engine and cooling system to cool down. In case of scalding, rinse immediately with lukewarm water.

Tip

Seal the air filter box at the edges to prevent dirt from entering.

Info

Check the air filter approx. every 30 minutes.

– Adjust the secondary ratio to the nature of the terrain.

Info

The engine oil heats up quickly if the clutch needs to be activated frequently because the secondary ratio is too long.

– Clean the chain.

Chain cleaner ( p. 96)

600868-01

– Clean the radiator fins. – Carefully align bent radiator fins. – Check the coolant level. ( p. 59)

6.8Preparations for riding at low temperatures and in snow

–

Seal the air filter box. x

Tip

Seal the air filter box at the edges to prevent dirt from entering.

–

Clean the air filter. x ( p. 63)

Info

Check the air filter approx. every 30 minutes.

– Mount the rain cover for the air filter.

600870-01

Rain cover for air filter (59006021000)

Info

Follow the KTM PowerParts mounting instructions.

– Adjust the carburetor jetting and setting.

Info

The recommended carburetor tuning is available from your authorized KTM workshop.

RIDING INSTRUCTIONS 19

7.1Checks before putting into operation

Info

Make sure that the motorcycle is in a perfect technical condition before use. In the interests of riding safety, make a habit of making a general check before you ride.

– Check the gear oil level. ( p. 68) – Check the chain tension. ( p. 40) – Check the chain for dirt. ( p. 39) – Check the tire condition. ( p. 53) – Check the tire air pressure. ( p. 54) – Check the front brake fluid level. ( p. 43) – Check the rear brake fluid level. ( p. 47) – Check the front brake linings. ( p. 44) – Check the rear brake linings. ( p. 48) – Check the brake system function. – Check the coolant level. ( p. 59) – Check the settings of all controls and ensure that they can be operated smoothly.

7.2Starting

Danger

Danger of poisoning Exhaust gases are poisonous and inhaling them may result in unconsciousness and/or death.

– When running the engine, always make sure there is sufficient ventilation, and do not start or run the engine in an enclosed

space without an effective exhaust extraction system.

Note

Engine failure High engine speeds in cold engines have a negative effect on the service life of the engine.

– Always warm up the engine at low engine speeds.

Info

If the motorcycle is unwilling to start, the cause can be old fuel in the float chamber. The flammable elements of the fuel evaporate after a long time of standing. If the float chamber is filled with fresh fuel, the engine starts immediately.

Engine has been out of use for more than one week

–

Empty the carburetor float chamber. x ( p. 68)

– Turn handle  of the fuel tap to the ON position. (Figure B00003-10 p. 11)

Fuel can flow from the fuel tank to the carburetor.

– Remove the motorcycle from the stand. – Shift gear to neutral.

The engine is cold

– Pull choke lever out as far as possible.

– Forcefully step on the kickstarter, pushing it all the way down.

Info

Do not open the throttle.

RIDING INSTRUCTIONS 20

7.3Starting up

Info

The plug-in stand must be removed before riding.

– Pull the clutch lever, engage 1st gear, release the clutch lever slowly and simultaneously open the throttle carefully.

7.4Shifting, riding

Warning

Danger of accidents If you change down at high engine speed, the rear wheel can lock up.

– Do not change into a low gear at high engine speed. The engine overspeeds and the rear wheel can block.

Info

If you hear unusual noises while riding, stop immediately, switch off the engine and contact an authorized KTM workshop. First gear is used for starting off or for steep inclines.

– When conditions allow (incline, road situation, etc.), you can shift into a higher gear. To do so, release the throttle while simulta-

neously pulling the clutch lever, shift into the next gear, release the clutch and open the throttle.

– If the choke function was activated, deactivate it after the engine has warmed up. – When you reach maximum speed after fully opening the throttle, turn back the throttle to about ¾ of its range. This barely reduces

vehicle speed but lowers fuel consumption considerably.

– Always open the throttle only as much as the engine can handle – abrupt throttle opening increases fuel consumption. – To shift down, brake and close the throttle at the same time. – Pull the clutch lever and shift into a lower gear, release the clutch lever slowly and open the throttle or shift again. – Switch off the engine if you expect to be standing for a long time.

Guideline

≥ 2 min

– Avoid frequent and longer slipping of the clutch. This heats the engine oil, the engine and the cooling system. – Ride with a lower engine speed instead of with a high engine speed and a slipping clutch.

7.5Braking

Warning

Danger of accidents If you brake too hard, the wheels can lock.

– Adapt your braking to the traffic situation and the road conditions.

Warning

Danger of accidents Reduced braking efficiency caused by spongy pressure point of front or rear brake.

– Check the brake system and do not continue riding. (Your authorized KTM workshop will be glad to help.)

Warning

Danger of accidents Reduced braking due to wet or dirty brakes.

– Clean or dry dirty or wet brakes by riding and braking gently.

– On sandy, wet or slippery surfaces, use the rear brake. – Braking should always be completed before you go into a bend. Change down to a lower gear appropriate to your road speed. – On long downhill stretches, use the braking effect of the engine. Change down one or two gears, but do not overstress the engine.

In this way, you have to brake far less and the brakes do not overheat.

RIDING INSTRUCTIONS 21

7.6Stopping, parking

Warning

Risk of misappropriation Usage by unauthorized persons.

– Never leave the vehicle while the engine is running. Secure the vehicle against use by unauthorized persons.

Warning

Danger of burns Some vehicle components get very hot when the vehicle is in use.

– Do not touch hot components such as exhaust system, radiator, engine, shock absorber and brakes. Allow these compo-

nents to cool down before starting work on them.

Note

Danger of damage The parked vehicle can roll away or fall over.

– Always place the vehicle on a firm and even surface.

Note

Fire hazard Some vehicle components become very hot when the vehicle is operated.

– Do not park the vehicle near flammable or explosive substances. Do not place objects on the vehicle while it is still warm from

being run. Always let the vehicle cool first.

Note

Material damage Damage and destruction of components by excessive load.

– The side stand is designed for the weight of the motorcycle only. Do not sit on the motorcycle when it is supported by the side

stand only. The side stand and/or the frame could be damaged and the motorcycle could fall over.

– Brake the motorcycle. – Shift gear to neutral. – Press and hold the short circuit button while the engine is idling until the engine stops. – Turn handle  of the fuel tap to the OFF position. (Figure B00003-10 p. 11) – Insert the plug-in stand on the left side of the wheel spindle. – Park the motorcycle on firm ground.

7.7Refueling

Danger

Fire hazard Fuel is highly flammable.

– Never refuel the vehicle near open flames or burning cigarettes, and always switch off the engine first. Be careful that no

fuel is spilt, especially on hot vehicle components. Clean up spilt fuel immediately.

– Fuel in the fuel tank expands when warm and can escape if the tank is overfilled. See the notes on refueling.

Warning

Danger of poisoning Fuel is poisonous and a health hazard.

– Avoid contact of the fuel with skin, eyes and clothing. Do not inhale fuel vapors. If fuel gets into your eyes, rinse imme-

diately with water and contact a doctor. Wash affected skin areas immediately with soap and water. If fuel is swallowed, contact a doctor immediately. Change clothing that has come into contact with fuel.

Warning

Environmental hazard Improper handling of fuel is a danger to the environment.

– Do not allow fuel to get into the ground water, the ground, or the sewage system.

– Switch off the engine. – Open the filler cap. ( p. 11)

RIDING INSTRUCTIONS 22

– Fill the fuel tank with fuel up to measurement .

Guideline

Measurement of  35 mm (1.38 in)

400382-10

Total fuel tank capacity, approx.

– Close the filler cap. ( p. 11)

8 l (2.1 US gal) Super unleaded gasoline, mixed with

2-stroke engine oil (1:40) ( p. 95) (125 SX, 150 SX)

Super unleaded gasoline, mixed with 2-stroke engine oil (1:60) ( p. 95) (250 SX)

SERVICE SCHEDULE 23

8.1Important maintenance work that must be done in an authorized KTM workshop

S10N S20A S40A

Engine Check the gear oil level. ( p. 68) • •

Change the gear oil. x ( p. 69) Check spark plug and replace if required. x Clean the spark plug connectors and check for tightness. x

Check that the screws in the shift lever and the kickstarter are tight. • • • Check the engine mounting screws for tightness. • • •

Carburetor Check intake flange and carburetor connection boot for cracks and leakage. • •

Check idle. • • Check vent hoses for damage and routing without sharp bends. • •

Attachments Check the cooling system for leakage. • •

Check the antifreeze and coolant level. ( p. 58) • • Check the exhaust system for leakage and looseness. • • Check the cables for damage, smooth operation and routing without sharp bends. • • • Check the fluid level of the hydraulic clutch. ( p. 64) • • •

Clean the air filter. x ( p. 63)

Check the cables for damage and routing without sharp bends. • •

Brakes Check the front brake linings. ( p. 44) • •

Check the rear brake linings. ( p. 48) • • Check the brake discs. ( p. 42) • • Check the front brake fluid level. ( p. 43) • • • Check the rear brake fluid level. ( p. 47) • • • Check the brake lines for damage and leakage. • • Check the free travel of the hand brake lever. ( p. 43) • • • Check the free play of the foot brake lever. ( p. 46) • • • Check the brake system function. • • • Check the screws and guide bolts of the brake system for tightness. • • •

Chassis

Wheels Check the spoke tension. ( p. 54) • • •

Check the shock absorber and fork for leakage and functioning. x

Clean the dust boots of the fork legs. ( p. 32) • • • Bleed the fork legs. ( p. 32) • • • Check the swingarm bearing. • • Check the frame and swingarm for damage. • • Check the play of the steering head bearing. ( p. 33) • • Check all screws to see if they are tight. • •

Check the wheel hubs for damage. • • • Check rim run-out. • • • Check the tire condition. ( p. 53) • • • Check the tire air pressure. ( p. 54) • • • Check chain wear. ( p. 40) • • • Check the chain tension. ( p. 40) • • • Clean the chain. ( p. 39) • • • Check the wheel bearing for play. • • Clean and grease the adjusting screws of chain adjuster. • • •

• •

• • •

• •

• • •

S10N: Once after 10 service hours - corresponds to about 70 liters of fuel (18.5 US gal) S20A: Every 20 service hours - corresponds to about 140 liters of fuel (37 US gal) S40A: Every 40 service hours - corresponds to about 280 liters of fuel (74 US gal) / after a race

SERVICE SCHEDULE 24

8.2Important maintenance work to be carried out by an authorized KTM workshop (as additional order)

S10A S20N S20A S30A S40A S80A J1A

Check/set the carburetor components. x Check the intake diaphragm. x Check the clutch lining discs. x Check the length of the clutch springs. x Check the cylinder and piston. x Check the seating of the piston pin. x

Check exhaust control for functioning and smooth operation,

clean. x

• • •

Change the crankshaft main bearing. x Change the conrod bearing. x Fully check the transmission. x Check the shift mechanism. x Conduct a major fork service. x Conduct a minor fork service. x Perform a shock absorber service. x

•

• • • • •

• • •

• •

Grease the steering head bearing. x ( p. 37) Change the foot brake cylinder seals. x Change the glass fiber yarn filling of the main silencer. x

( p. 61)

• • •

• •

Change the hydraulic clutch fluid. x ( p. 65)

Change the front brake fluid. • Change the rear brake fluid. • Treat electric contacts with contact spray. •

•

S10A: Every 10 service hours - corresponds to about 70 liters of fuel (18.5 US gal) S20N: Once after 20 service hours - corresponds to about 140 liters of fuel (37 US gal) S20A: Every 20 service hours - corresponds to about 140 liters of fuel (37 US gal) S30A: Every 30 service hours - corresponds to about 210 liters of fuel (55.5 US gal) S40A: Every 40 service hours - corresponds to about 280 liters of fuel (74 US gal) S80A: Every 80 service hours - corresponds to about 560 liters of fuel (148 US gal) J1A: annually

8.3Important checks and maintenance work to be carried out by the rider

Check the gear oil level. ( p. 68) • Check the front brake fluid level. ( p. 43) • Check the rear brake fluid level. ( p. 47) • Check the front brake linings. ( p. 44) • Check the rear brake linings. ( p. 48) • Check and adjust the cables. • Bleed the fork legs. ( p. 32) • Clean the dust boots of the fork legs. ( p. 32) • Clean the chain. ( p. 39) • Check the chain tension. ( p. 40) • Check chain wear. ( p. 40) • Check the rear sprocket/engine sprocket for wear. ( p. 40) •

Clean the air filter. x ( p. 63)

Check the tire air pressure. ( p. 54) • Check the tire condition. ( p. 53) •

NB1A

•

SERVICE SCHEDULE 25

NB1A

Check the coolant level. ( p. 59) •

Empty the carburetor float chamber. x ( p. 68)

Check all controls for smooth operation. • Check braking. • Check all screws, nuts and hose clamps regularly for tightness. •

NB1A: Depending on conditions of use according to requirements.

•

MAINTENANCE WORK ON CHASSIS AND ENGINE 26

9.1Jacking up the motorcycle

Note

Danger of damage The parked vehicle can roll away or fall over.

– Always place the vehicle on a firm and even surface.

– Jack up the motorcycle underneath the engine. The wheels must no longer touch

the ground.

Work stand (54829055000)

B00011-10

9.2Removing the motorcycle from the work stand

– Secure the motorcycle against falling over.

Note

Danger of damage The parked vehicle can roll away or fall over.

– Always place the vehicle on a firm and even surface.

– Remove the motorcycle from the work stand. – Remove the work stand.

9.3Checking the basic chassis setting with the rider's weight

Info

When adjusting the basic chassis setting, first adjust the shock absorber and then the fork.

– For optimal motorcycle riding characteristics and to avoid damage to forks, shock absorbers, swing arm and frame, the basic set-

tings of the suspension components must match your body weight.

– As delivered, KTM offroad motorcycles are adjusted for a standard rider weight (with full protective clothing).

Guideline

Standard rider weight 75… 85 kg (165… 187 lb.)

– If your weight is above or below the standard range, you need to adjust the basic setting of the suspension components accord-

ingly.

– Small weight differences can be compensated by adjusting the spring preload, but in the case of large weight differences, the

springs must be replaced.

9.4Compression damping of shock absorber

The shock absorber can separately regulate compression damping in the low- and high-speed ranges (Dual Compression Control). Here, low-speed and high-speed refer to the movement of the shock absorber during compression and not the riding speed of the motorcycle. Changes in the settings in the low-speed range have an impact on the high-speed range and vice versa.

9.5Adjusting the high-speed compression damping of the shock absorber

Danger

Danger of accidents Disassembly of pressurized parts can lead to injury.

– The shock absorber is filled with high density nitrogen. Adhere to the description provided. (Your authorized KTM workshop

will be glad to help.)

Info

The high-speed setting can be seen during the fast compression of the shock absorber.

MAINTENANCE WORK ON CHASSIS AND ENGINE 27

– Turn adjusting screw  all the way clockwise with a ring wrench.

Info

Do not loosen nut !

– Turn back counterclockwise by the number of turns corresponding to the shock

absorber type. Guideline

(125 SX, 150 SX)

400208-10

Compression damping, high-speed

Comfort 2 turns Standard 1.5 turns Sport 1 turn

(250 SX)

Compression damping, high-speed

Comfort 2 turns Standard 1.5 turns Sport 1 turn

Info

Turn clockwise to increase damping, turn counterclockwise to reduce damping.

9.6Adjusting the low-speed compression damping of the shock absorber

Danger

Danger of accidents Disassembly of pressurized parts can lead to injury.

– The shock absorber is filled with high density nitrogen. Adhere to the description provided. (Your authorized KTM workshop

will be glad to help.)

Info

The low-speed setting can be seen during the slow to normal compression of the shock absorber.

– Turn adjusting screw  clockwise with a screwdriver up to the last perceptible

click.

Info

Do not loosen nut !

– Turn back counterclockwise by the number of clicks corresponding to the shock

absorber type. Guideline

400209-10

(125 SX, 150 SX)

Compression damping, low-speed

Comfort 17 clicks Standard 15 clicks Sport 13 clicks

(250 SX)

Compression damping, low-speed

Comfort 17 clicks Standard 15 clicks Sport 13 clicks

Info

Turn clockwise to increase damping, turn counterclockwise to reduce damping.

MAINTENANCE WORK ON CHASSIS AND ENGINE 28

00AA

9.7Adjusting the rebound damping of the shock absorber

Danger

Danger of accidents Disassembly of pressurized parts can lead to injury.

– The shock absorber is filled with high density nitrogen. Adhere to the description provided. (Your authorized KTM workshop

will be glad to help.)

– Turn adjusting screw  clockwise up to the last perceptible click.

Info

Do not loosen nut !

– Turn back counterclockwise by the number of clicks corresponding to the shock

absorber type. Guideline

(125 SX, 150 SX)

400210-10

Rebound damping

Comfort 24 clicks Standard 22 clicks Sport 22 clicks

(250 SX)

Rebound damping

Comfort 24 clicks Standard 22 clicks Sport 22 clicks

9.8Measuring the sag of the unloaded rear wheel

– Jack up the motorcycle. ( p. 26) – Measure the distance – as vertical as possible – between the rear axle and a fixed

point, for example, a mark on the side cover.

– Make a note of the value as measurement . – Remove the motorcycle from the work stand. ( p. 26)

400220-10

Info

Turn clockwise to increase damping, turn counterclockwise to reduce damping.

MAINTENANCE WORK ON CHASSIS AND ENGINE 29

000BB

9.9Checking the static sag of the shock absorber

– Measure distance  of the unloaded rear wheel. ( p. 28) – Ask someone to help you by holding the motorcycle upright. – Measure the distance between the rear axle and the fixed point again. – Make a note of the value as measurement .

Info

The static sag is the difference between measurements  and .

– Check the static sag.

(125 SX, 150 SX)

Static sag 33 mm (1.3 in)

(250 SX)

Static sag 33 mm (1.3 in)

» If the static sag is less or more than the specified value:

–

Adjust the spring preload of the shock absorber. x ( p. 29)

400221-10

9.10Checking the riding sag of the shock absorber

– Measure distance  of the unloaded rear wheel. ( p. 28) – With another person holding the motorcycle, the rider, wearing a full set of protec-

tive clothing, sits on the saddle in the normal sitting position (feet on footrests) and bounces up and down a few times until the rear suspension levels out.

– The other person now measures the distance between the rear axle and a fixed

point.

– Make a note of the value as measurement .

Info

The riding sag is the difference between measurements  and .

– Check the riding sag.

Guideline

(125 SX, 150 SX)

Riding sag 107 mm (4.21 in)

(250 SX)

Riding sag 105 mm (4.13 in)

» If the riding sag differs from the specified measurement:

400222-10

9.11Adjusting the spring preload of the shock absorber x

–

Adjust the riding sag. x ( p. 30)

Danger

Danger of accidents Disassembly of pressurized parts can lead to injury.

– The shock absorber is filled with high density nitrogen. Adhere to the description provided. (Your authorized KTM workshop

will be glad to help.)

Info

Before changing the spring preload, make a note of the present setting, e.g., by measuring the length of the spring.

–

Remove the shock absorber. x ( p. 30)

– After removing the shock absorber, clean it thoroughly.

MAINTENANCE WORK ON CHASSIS AND ENGINE 30

22 11

– Unscrew screw . – Turn adjusting ring  until the spring is no longer under tension.

Combination wrench (50329080000) Hook wrench (T106S)

– Measure the overall spring length when not under tension. – Tighten the spring by turning adjusting ring  to measurement .

Guideline

(125 SX, 150 SX)

Spring preload 5 mm (0.2 in)

(250 SX)

Spring preload 6 mm (0.24 in)

Info

Depending on the static sag and/or the riding sag, it may be necessary to increase or decrease the spring preload.

– Tighten screw .

400216-10

Guideline

Screw, shock absorber adjusting ring M6 5 Nm (3.7 lbf ft)

–

Install the shock absorber. x ( p. 31)

9.12Adjusting the riding sag x

–

Remove the shock absorber. x ( p. 30)

– After removing the shock absorber, clean it thoroughly. – Choose and mount a suitable spring.

Guideline

(125 SX, 150 SX)

Spring rate

Weight of rider: 65… 75 kg (143… 165 lb.) 60 N/mm (343 lb/in) Weight of rider: 75… 85 kg (165… 187 lb.) 63 N/mm (360 lb/in) Weight of rider: 85… 95 kg (187… 209 lb.) 66 N/mm (377 lb/in)

(250 SX)

Spring rate

Weight of rider: 65… 75 kg (143… 165 lb.) 66 N/mm (377 lb/in) Weight of rider: 75… 85 kg (165… 187 lb.) 69 N/mm (394 lb/in) Weight of rider: 85… 95 kg (187… 209 lb.) 72 N/mm (411 lb/in)

Info

The spring rate is shown on the outside of the spring.

–

Install the shock absorber. x ( p. 31)

– Check the static sag of the shock absorber. ( p. 29) – Check the riding sag of the shock absorber. ( p. 29) – Adjust the rebound damping of the shock absorber. ( p. 28)

9.13Removing the shock absorber x

– Jack up the motorcycle. ( p. 26) – Remove screw  and lower the rear wheel with the swing arm as far as possible

without blocking the rear wheel. Fix the rear wheel in this position.

– Remove screw , push splash protector  to the side, and remove the shock

absorber.

B00012-10

MAINTENANCE WORK ON CHASSIS AND ENGINE 31

9.14Installing the shock absorber x

– Push splash protector  to the side and position the shock absorber. Mount and

tighten screw . Guideline

Screw, top shock absorber M12 80 Nm

– Mount and tighten screw .

Guideline

Screw, bottom shock

B00012-11

absorber

Info

The heim joint for the shock absorber at the swing arm is Teflon coated. It must not be greased with grease or with other lubricants. Lubricants dissolve the Teflon coating, thereby drastically reducing the service life.

– Remove the motorcycle from the work stand. ( p. 26)

9.15Checking the basic setting of the fork

Info

For various reasons, no exact riding sag can be determined for the forks.

(59 lbf ft)

M12 80 Nm

(59 lbf ft)

Loctite®243™

– As with the shock absorber, smaller weight differences can be compensated by the

spring preload.

– However, if your fork often bottoms out (hard end stop on compression), you must

fit harder springs to avoid damage to the fork and frame.

400189-01

9.16Adjusting the compression damping of the fork

Info

The hydraulic compression damping determines the fork suspension behavior.

– Turn adjusting screws  clockwise all the way.

Info

Adjusting screws  are located at the top end of the fork legs. Make the same adjustment on both fork legs.

– Turn back counterclockwise by the number of clicks corresponding to the fork type.

Guideline

(125 SX, 150 SX)

B00018-11

Compression damping

Comfort 14 clicks Standard 12 clicks Sport 10 clicks

(250 SX)

Compression damping

Comfort 14 clicks Standard 12 clicks Sport 10 clicks

MAINTENANCE WORK ON CHASSIS AND ENGINE 32

Info

Turn clockwise to increase damping, turn counterclockwise to reduce damping.

9.17Adjusting the rebound damping of the fork

Info

The hydraulic rebound damping determines the fork suspension behavior.

– Remove protection covers . – Turn adjusting screws  clockwise all the way.

Info

The adjusting screws  are located at the bottom end of the fork legs. Make the same adjustment on both fork legs.

– Turn back counterclockwise by the number of clicks corresponding to the fork type.

Guideline

B00067-10

(125 SX, 150 SX)

Rebound damping

Comfort 14 clicks Standard 12 clicks Sport 10 clicks

9.18Bleeding the fork legs

(250 SX)

Rebound damping

Comfort 14 clicks Standard 12 clicks Sport 10 clicks

Info

Turn clockwise to increase damping, turn counterclockwise to reduce damping.

– Mount protection covers .

– Jack up the motorcycle. ( p. 26) – Remove bleeder screws  briefly.

Any excess pressure escapes from the interior of the fork.

– Mount and tighten bleeder screws. – Remove the motorcycle from the work stand. ( p. 26)

B00018-10

9.19Cleaning the dust boots of the fork legs

– Jack up the motorcycle. ( p. 26) – Loosen the fork protection. ( p. 33)

MAINTENANCE WORK ON CHASSIS AND ENGINE 33

– Push dust boots  of both fork legs downwards.

Info

The dust boots should remove dust and coarse dirt particles from the fork tubes. Over time, dirt can penetrate behind the dust boots. If this dirt is not removed, the oil seals behind can start to leak.

Warning

500088-10

– Clean and oil the dust boots and inner fork tube of both fork legs.

– Press the dust boots back into their normal position. – Remove excess oil. – Position the fork protection. ( p. 33) – Remove the motorcycle from the work stand. ( p. 26)

9.20Loosening the fork protection

– Remove screws  and take off the clamp. – Remove screws  on the left fork leg. Push the fork protection downwards. – Remove the screws on the right fork leg. Push the fork protection downwards.

Danger of accidents Reduced braking efficiency due to oil or grease on the brake discs.

– Always keep the brake discs free of oil and grease, and clean them with

brake cleaner when necessary.

Universal oil spray ( p. 97)

B00013-11

9.21Positioning the fork protection

– Position the fork protection on the left fork leg. Mount and tighten screws .

Guideline

Remaining screws, chassis M6 10 Nm (7.4 lbf ft)

– Position the brake line. Position the clamp and mount and tighten screws . – Position the fork protection on the right fork leg. Mount and tighten the screws.

Guideline

Remaining screws, chassis M6 10 Nm (7.4 lbf ft)

B00013-10

9.22Checking the play of the steering head bearing

Warning

Danger of accidents Unstable vehicle handling from incorrect steering head bearing play.

– Adjust the steering head bearing play without delay. (Your authorized KTM workshop will be glad to help.)

Info

If the bike is ridden for a lengthy period with play in the steering head bearing, the bearing and the bearing seats in the frame can be damaged after time.

– Jack up the motorcycle. ( p. 26)

MAINTENANCE WORK ON CHASSIS AND ENGINE 34

– Move the handlebar to the straight-ahead position. Move the fork legs to and fro in

the direction of travel.

No play should be noticeable in the steering head bearing.

» If there is noticeable play present:

–

Adjust the play of the steering head bearing. x ( p. 34)

– Move the handlebar to and fro over the entire steering range.

The handlebar must be able to move easily over the entire steering range. There

400387-10

9.23Adjusting the play of the steering head bearing x

should be no perceptible detent positions.

» If detent positions are noticeable:

–

Adjust the play of the steering head bearing. x ( p. 34)

– Check the steering head bearing and replace if required.

– Remove the motorcycle from the work stand. ( p. 26)

– Jack up the motorcycle. ( p. 26) – Loosen screws . Remove screw . – Loosen and retighten screw .

Guideline

Screw, top steering head M20x1.5 10 Nm (7.4 lbf ft)

9.24Removing the fork legs x

B00019-10

B00020-10

– Using a plastic hammer, tap lightly on the upper triple clamp to avoid strains. – Tighten screws .

Guideline

Screw, top triple clamp M8 17 Nm

(12.5 lbf ft)

– Mount and tighten screw .

Guideline

Screw, top steering stem M8 17 Nm

Loctite®243™

(12.5 lbf ft)

– Check the play of the steering head bearing. ( p. 33)

–

Remove the front wheel. x ( p. 50)

– Remove screws  and take off the clamp. – Remove screws  and take off the brake caliper. – Allow the brake caliper and brake line to hang tension-free to the side.

– Unscrew screws . Take out the left fork leg. – Unscrew screws . Take out the right fork leg.

B00021-10

MAINTENANCE WORK ON CHASSIS AND ENGINE 35

9.25Installing the fork legs x

– Position the fork legs.

Info

The topmost milled groove in the fork leg must be flush to the upper edge of the upper triple clamp. Position bleeder screws  toward the front.

B00018-10

– Tighten screws .

Guideline

Screw, top triple clamp M8 17 Nm

(12.5 lbf ft)

– Tighten screws .

Guideline

Screw, bottom triple clamp M8 12 Nm (8.9 lbf ft)

B00021-11

– Position the brake caliper and mount and tighten screws .

Guideline

Screw, front brake caliper M8 25 Nm

(18.4 lbf ft)

Loctite®243™

B00020-11

9.26Removing the fork protector x

500105-10

9.27Installing the fork protector x

– Position the brake line. Put the clamp on, and mount and tighten screws .

–

Install the front wheel. x ( p. 51)

–

Remove the fork legs. x ( p. 34)

– Remove screws  on the left fork leg. Lift off the fork protector. – Remove the screws on the right fork leg. Lift off the fork protector.

– Position the fork protection on the left fork leg. Mount and tighten screws .

Guideline

Remaining screws, chassis M6 10 Nm (7.4 lbf ft)

500105-10

– Position the fork protection on the right fork leg. Mount and tighten the screws.

Guideline

Remaining screws, chassis M6 10 Nm (7.4 lbf ft)

–

Install the fork legs. x ( p. 35)

MAINTENANCE WORK ON CHASSIS AND ENGINE 36

0022 0

9.28Removing the lower triple clamp x

–

Remove the fork legs. x ( p. 34)

– Remove the start number plate. ( p. 37) – Remove the front fender. ( p. 37) – Remove screws  and hang the CDI control unit to the side.

Info

Do not unplug the CDI control unit.

– Remove screw . Remove screw , take off the top triple clamp with the handle-

bar and place it on one side.

Info

B00022-10

– Remove O-ring . Remove protective ring . – Take out the lower triple clamp with the steering stem. – Take out the upper steering head bearing.

Protect the motorcycle and its attachments against damage by covering them. Do not bend the cables and lines.

B00023-11

9.29Installing the lower triple clamp x

B00024-10

– Clean the bearing and sealing elements, check for damage, and grease.

Long-life grease ( p. 96)

– Insert the lower triple clamp with the steering stem. Mount the upper steering head

bearing.

Info

Check whether the top steering head seal  is correctly positioned.

– Push up protective ring  and O-ring .

– Position the upper triple clamp with the steering. – Mount and tighten screw .

Guideline

Screw, top steering head M20x1.5 10 Nm (7.4 lbf ft)

B00022-11

– Position the clutch line, wiring harness and CDI control unit. Mount and tighten

screws . Guideline

Remaining screws, chassis M6 10 Nm (7.4 lbf ft)

– Install the front fender. ( p. 37) – Install the start number plate. ( p. 38)

–

Install the fork legs. x ( p. 35)

MAINTENANCE WORK ON CHASSIS AND ENGINE 37

– Mount and tighten screw .

Guideline

B00019-11

9.30Greasing the steering head bearing x

800010-10

Screw, top steering stem M8 17 Nm

(12.5 lbf ft)

– Check that the wiring harness, throttle cables and brake and clutch lines can move

freely and are routed correctly.

– Check the play of the steering head bearing. ( p. 33)

–

Remove the lower triple clamp. x ( p. 36)

–

Install the lower triple clamp. x ( p. 36)

Loctite®243™

9.31Removing the front fender

9.32Installing the front fender

– Remove screws . Remove the front fender. – Make sure the spacers remain in place.

500092-10

– Ensure that the spacers are mounted in the fender. – Position the front fender. Mount and tighten screws .

Guideline

Remaining screws, chassis M6 10 Nm (7.4 lbf ft)

Info

Make sure the holding lugs engage in the start number plate.

500092-10

9.33Removing the start number plate

500123-10

– Remove screw  and take off the clamp. – Remove screw . Take off the start number plate.

MAINTENANCE WORK ON CHASSIS AND ENGINE 38

00BB

0022

9.34Installing the start number plate

– Position the start number plate. Mount and tighten screw .

Guideline

Remaining screws, chassis M6 10 Nm (7.4 lbf ft)

Info

Ensure that the holding lugs engage in the fender.

– Position the brake line. Position the clamp and mount and tighten screw .

500123-11

9.35Handlebar position

On the upper triple clamp, there are two holes a distance of  apart.

Hole distance A 15 mm (0.59 in)

The holes on the handlebar support are placed at a distance of  from the center.

Hole distance B 3.5 mm (0.138 in)

The handlebar can be mounted in four different positions. In this way, the handlebar can be mounted in the position that is most comfortable for the rider.

B00025-11

9.36Adjusting the handlebar position x

B00025-10

– Remove the four screws . Remove the handlebar clamp. Remove the handlebar

and lay it to one side.

Info

Protect the motorcycle and its attachments against damage by covering them. Do not bend the cables and lines.

– Remove the two screws . Remove the handlebar support. – Place the handlebar support in the required position. Mount and tighten the two

screws . Guideline

Screw, handlebar support M10 40 Nm

(29.5 lbf ft)

Info

Position the left and right handlebar supports evenly.

– Position the handlebar.

Info

Make sure cables and wiring are positioned correctly.

Loctite®243™

– Position the handlebar clamp. Mount and evenly tighten the four screws .

Guideline

Screw, handlebar clamp M8 20 Nm

(14.8 lbf ft)

MAINTENANCE WORK ON CHASSIS AND ENGINE 39

9.37Checking the play in the throttle cable

– Move the handlebar to the straight-ahead position. – Push back bellows . – Pull back the throttle cable casing until you sense a resistance. – Now check throttle cable play .

Play in throttle cable 3… 5 mm (0.12… 0.2 in)

» If the throttle cable play does not meet specifications:

–

Adjust the play in the throttle cable. x ( p. 39)

B00026-10

9.38Adjusting the play in the throttle cable x

– Push on bellows . Check the throttle grip for smooth operation.

– Move the handlebar to the straight-ahead position. – Push back bellows . – Loosen nut . Turn adjusting screw  in as far as possible. – Turn the adjusting screw so that there is play  at the outer casing of the throttle

cable. Guideline

Play in throttle cable 3… 5 mm (0.12… 0.2 in)

B00026-11

9.39Checking the chain for dirt

– Tighten the nut. – Push on bellows . Check the throttle grip for smooth operation.

– Check the chain for heavy soiling.

» If the chain is very dirty:

– Clean the chain. ( p. 39)

400678-01

9.40Cleaning the chain

Warning

Danger of accidents Oil or grease on the tires reduces their grip.

– Remove oil and grease with a suitable cleaning material.

Warning

Danger of accidents Reduced braking efficiency due to oil or grease on the brake discs.

– Always keep the brake discs free of oil and grease, and clean them with brake cleaner when necessary.

Warning

Environmental hazard Hazardous substances cause environmental damage.

– Oil, grease, filters, fuel, cleaners, brake fluid, etc., should be disposed of as stipulated in applicable regulations.

Info

The service life of the chain depends largely on its maintenance.

MAINTENANCE WORK ON CHASSIS AND ENGINE 40

– Clean the chain regularly and then treat with chain spray.

Chain cleaner ( p. 96) Off-road chain spray ( p. 96)

400725-01

9.41Checking the chain tension

Warning

Danger of accidents Danger caused by incorrect chain tension.

– If the chain tension is too high, the components of the secondary power train (chain, engine sprocket, rear sprocket, bear-

ings in transmission and rear wheel) are under additional load. Apart from premature wear, in extreme cases the chain can rupture or the countershaft of the transmission can break. On the other hand, if the chain is loose, it can fall off the engine sprocket or the rear sprocket and block the rear wheel or damage the engine. Check the chain tension and correct if necessary.

– Jack up the motorcycle. ( p. 26) – Push the chain at the end of the chain sliding component upwards to measure

chain tension .

Info

The upper chain section  must be taut. Chain wear is not always even, so you should repeat this measurement at different chain positions.

Chain tension 8… 10 mm (0.31… 0.39 in)

400213-10

9.42Checking the rear sprocket/engine sprocket for wear

400227-01

9.43Checking chain wear

» If the chain tension does not meet specifications:

– Adjust the chain tension. ( p. 41)

– Remove the motorcycle from the work stand. ( p. 26)

– Check the rear sprocket/engine sprocket for wear.

» If the rear sprocket/engine sprocket are worn:

– Replace the rear sprocket/engine sprocket.

– Check the chain guide for tightness and wear.

– Jack up the motorcycle. ( p. 26)

Info

When fitting the chain joint, always make sure that the closed side of the joint faces forward (riding direction). The engine sprocket, rear sprocket and chain should always be replaced together.

MAINTENANCE WORK ON CHASSIS AND ENGINE 41

1 2 3 16 17 18

– Shift gear to neutral. – Pull on the upper part of the chain with the specified weight .

Guideline

Weight, chain wear measurement 10… 15 kg (22… 33 lb.)

– Measure the distance  of 18 chain links in the lower chain section.

Info

Chain wear is not always even, so you should repeat this measurement at different chain positions.

Maximum distance  at the longest chain section

» If the distance  is greater than the specified measurement:

– Replace the chain.

Info

When you replace the chain, you should also replace rear sprocket and engine sprocket.

400226-10

– Remove the motorcycle from the work stand. ( p. 26)

9.44Adjusting the chain tension

Warning

Danger of accidents Danger caused by incorrect chain tension.

– If the chain tension is too high, the components of the secondary power train (chain, engine sprocket, rear sprocket, bear-

– Jack up the motorcycle. ( p. 26) – Push the chain at the end of the chain sliding component upwards to measure

chain tension .

New chains wear out faster on old, worn sprockets.

272 mm (10.71 in)

Info

The upper chain section  must be taut. Chain wear is not always even, so you should repeat this measurement at different chain positions.

400213-10

MAINTENANCE WORK ON CHASSIS AND ENGINE 42

– Loosen nut . – Loosen nuts . – Adjust the chain tension by turning the adjusting screws  to the left and right.

Guideline

Chain tension 8… 10 mm (0.31… 0.39 in) Turn adjusting screws  on the left and right so that the markings on the left

and right chain adjusters are in the same position relative to reference marks . The rear wheel is then correctly aligned.

– Tighten nuts . – Make sure that chain adjusters  are fitted correctly on adjusting screws . – Tighten nut .

Guideline

Nut, rear wheel spindle M20x1.5 80 Nm (59 lbf ft)

Info

The wide adjustment range of the chain adjusters (32 mm) enables different secondary ratios with the same chain length.

400225-10

– Remove the motorcycle from the work stand. ( p. 26)

Chain adjusters  can be turned by 180°.

9.45Adjusting the chain guide x

9.46Checking the brake discs

– Unscrew screw . Remove screw . Swing the chain guide down.

Condition

Number of teeth: ≤ 44 teeth – Insert collar bushing  in hole . Position the chain guide. – Mount and tighten screw . Tighten screw .

Guideline

Remaining screws, chassis M6 10 Nm

(7.4 lbf ft)

Condition

Number of teeth: ≥ 45 teeth – Insert collar bushing  in hole . Position the chain guide. – Mount and tighten screw . Tighten screw .

Guideline

Remaining screws, chassis M6 10 Nm

(7.4 lbf ft)

400224-10

Warning

Danger of accidents Reduced braking efficiency due to worn brake disc(s).

– Change the worn brake disc(s) without delay. (Your authorized KTM workshop will be glad to help.)

– Check the thickness of the front and rear brake discs at several places on the disc

to see if it conforms to measurement .

Info

Wear reduces the thickness of the brake disc around the area used by the brake linings.

Brake discs - wear limit

400257-10

Front 2.5 mm (0.098 in) Rear 3.5 mm (0.138 in)

MAINTENANCE WORK ON CHASSIS AND ENGINE 43

» If the brake disc thickness is less than the specified value:

– Change the brake disc.

– Check the front and rear brake discs for damage, cracking and deformation.

» If the brake disc exhibits damage, cracking or deformation:

– Change the brake disc.

9.47Checking the free travel of the hand brake lever

Warning

Danger of accidents Brake system failure.

– If there is no free travel on the hand brake lever, pressure builds up in the front brake circuit. The front brake can fail due

to overheating. Adjust free travel on hand brake lever according to specifications.

– Push the hand brake lever forward and check free travel .

Free play of hand brake lever ≥ 3 mm (≥ 0.12 in)

» If the free travel does not meet specifications:

– Adjust the basic position of the hand brake lever. ( p. 43)

400196-11

9.48Adjusting the basic position of the hand brake lever

– Check the free travel of the hand brake lever. ( p. 43) – Adjust the basic setting of the hand brake lever to your hand size by turning adjust-

ing screw .

Info

Turn the adjusting screw clockwise to increase the distance between the hand brake lever and the handlebar. Turn the adjusting screw counterclockwise to decrease the distance between the hand brake lever and the handlebar.

400196-12

The range of adjustment is limited. Turn the adjusting screw by hand only, and do not apply any force. Do not make any adjustments while riding!

9.49Checking the front brake fluid level

Warning

Danger of accidents Failure of the brake system.

– If the brake fluid level falls below the MIN mark, this indicates a leakage in the brake system or worn-out brake linings.

Check the brake system and do not continue riding. (Your authorized KTM workshop will be glad to help.)

Warning

Danger of accidents Reduced braking effect caused by old brake fluid.

– Change the brake fluid of the front and rear brakes according to the service schedule. (Your authorized KTM workshop will

be glad to help.)

B00070-10

– Move the brake fluid reservoir mounted on the handlebar to a horizontal position. – Check the brake fluid level in the viewer .

» If the brake fluid is below the MIN marking:

–

Add front brake fluid. x ( p. 44)

MAINTENANCE WORK ON CHASSIS AND ENGINE 44

9.50Adding front brake fluid x

Warning

Danger of accidents Failure of the brake system.

– If the brake fluid level falls below the MIN mark, this indicates a leakage in the brake system or worn-out brake linings.

Check the brake system and do not continue riding. (Your authorized KTM workshop will be glad to help.)

Warning

Skin irritation Brake fluid can cause skin irritation on contact.

– Avoid contact with skin and eyes, and keep out of the reach of children. – Wear suitable protective clothing and goggles. – If brake fluid gets into your eyes, rinse thoroughly with water and contact a doctor immediately.

Warning

Danger of accidents Reduced braking effect caused by old brake fluid.

– Change the brake fluid of the front and rear brakes according to the service schedule. (Your authorized KTM workshop will

be glad to help.)

Warning

Environmental hazard Hazardous substances cause environmental damage.

– Oil, grease, filters, fuel, cleaners, brake fluid, etc., should be disposed of as stipulated in applicable regulations.

Info

Never user DOT 5 brake fluid! This is based on silicone oil and is colored purple. Oil seals and brake lines are not designed for DOT 5 brake fluid. Avoid contact between brake fluid and painted parts. Brake fluid attacks paint! Use only clean brake fluid from a sealed container!

– Move the brake fluid reservoir mounted on the handlebar to a horizontal position. – Remove screws . – Remove cover  with membrane . – Add brake fluid to level .

Guideline

Dimension  (brake fluid level below

5 mm (0.2 in)

top edge of container)

Brake fluid DOT 4 / DOT 5.1 ( p. 94)

– Position the cover with the membrane. Mount and tighten the screws.

Info

Clean up overflowed or spilt brake fluid immediately with water.

600706-10

9.51Checking the front brake linings

Warning

Danger of accidents Reduced braking efficiency caused by worn brake linings.

– Change worn brake linings immediately. (Your authorized KTM workshop will be glad to help.)

MAINTENANCE WORK ON CHASSIS AND ENGINE 45

– Check the brake linings for minimum thickness .

Minimum thickness  ≥ 1 mm (≥ 0.04 in)

» If the minimum thickness is less than specified:

–

Change the front brake linings. x ( p. 46)

– Check the brake linings for damage and cracking.

» If damage or cracking is visible:

–

Change the front brake linings. x ( p. 46)

400235-10

9.52Removing the front brake linings x

Warning

Danger of accident Brake system failure.

– Maintenance work and repairs must be carried out professionally. (Your authorized KTM workshop will be glad to help.)

– Press the brake caliper onto the brake disc by hand in order to push back the brake

pistons.

Info

Make sure when pushing back the brake pistons that you do not press the brake caliper against the spokes.

– Remove locking split pins , withdraw bolt , and take out the brake linings. – Remove screws  and take off the brake caliper.

B00055-11

9.53Installing the front brake linings x

– Clean the brake caliper and brake caliper support.

Warning

Danger of accidents Reduced braking efficiency due to oil or grease on the brake discs.

– Always keep the brake discs free of oil and grease, and clean them with brake cleaner when necessary.

Warning

Danger of accidents Reduced braking efficiency due to use of non-approved brake linings.

– Brake linings available from accessory suppliers are often not tested and approved for use on KTM vehicles. The construc-

tion and friction factor of the brake linings and therefore the brake power can differ considerably from the original KTM brake linings. If brake linings are used that differ from the originals, there is no guarantee that they comply with the original license. The vehicle no longer corresponds to the condition at delivery, and the warranty is no longer valid.

– Check the brake discs. ( p. 42) – Check that leaf spring  in the brake caliper and sliding plate  in the brake

caliper support are seated correctly.

Info

The arrow on the leaf spring points in the rotation direction of the brake disc.

400255-10

B00055-12

– Insert the brake linings, insert bolt , and mount locking split pins . – Position the brake caliper and mount and tighten screws .

Guideline

Screw, front brake caliper M8 25 Nm

Loctite®243™

(18.4 lbf ft)

– Operate the hand brake lever repeatedly until the brake linings lie on the brake disc

and there is a pressure point.

MAINTENANCE WORK ON CHASSIS AND ENGINE 46

9.54Changing the front brake linings x

Warning

Skin irritation Brake fluid can cause skin irritation on contact.

Warning

Danger of accidents Reduced braking effect caused by old brake fluid.

– Change the brake fluid of the front and rear brakes according to the service schedule. (Your authorized KTM workshop will

be glad to help.)

Warning

Environmental hazard Hazardous substances cause environmental damage.

– Oil, grease, filters, fuel, cleaners, brake fluid, etc., should be disposed of as stipulated in applicable regulations.

Info

–

Remove the front brake linings. x ( p. 45)

– Move the brake fluid reservoir mounted on the handlebar to a horizontal position. – Remove screws . – Remove cover  with membrane . – Press the brake piston back to its basic position and make sure that no brake fluid

overflows from the brake fluid reservoir.

–

Install the front brake linings. x ( p. 45)

– Add brake fluid to level .

Guideline

Dimension  (brake fluid level below

5 mm (0.2 in)

top edge of container)

Brake fluid DOT 4 / DOT 5.1 ( p. 94)

– Position the cover with the membrane. Mount and tighten the screws.

Info

Clean up overflowed or spilt brake fluid immediately with water.

600706-10

9.55Checking the free play of the foot brake lever

Warning

Danger of accidents Brake system failure.

– If there is no free travel on the foot brake pedal, pressure builds up on the rear brake circuit. The rear brake can fail due to

overheating. Adjust free travel on foot brake pedal according to specifications.

B00028-10

– Disconnect spring . – Move the foot brake lever back and forth between the end stop and the foot brake

cylinder piston bracket and check free travel . Guideline

Free play of foot brake lever 3… 5 mm (0.12… 0.2 in)

» If the free travel does not meet specifications:

MAINTENANCE WORK ON CHASSIS AND ENGINE 47

–

Adjust the basic position of the foot brake lever. x ( p. 47)

– Attach spring .

9.56Adjusting the basic position of the foot brake lever x

Warning

Danger of accidents Brake system failure.

– If there is no free travel on the foot brake pedal, pressure builds up on the rear brake circuit. The rear brake can fail due to

overheating. Adjust free travel on foot brake pedal according to specifications.

– Disconnect spring . – Loosen nut  and, with push rod , turn it back until you have maximum free

travel.

– To adjust the basic position of the foot brake lever individually, loosen nut  and

turn screw  accordingly.

Info

The range of adjustment is limited.

B00008-10

– Turn push rod  accordingly until you have free travel . If necessary, adjust the

basic position of the foot brake lever. Guideline

Free play of foot brake lever 3… 5 mm (0.12… 0.2 in)

– Hold screw  and tighten nut .

Guideline

Remaining screws, chassis M8 25 Nm

(18.4 lbf ft)

– Hold push rod  and tighten nut .

Guideline

Remaining nuts, chassis M6 15 Nm

(11.1 lbf ft)

– Attach spring .

9.57Checking the rear brake fluid level

Warning

Danger of accidents Failure of the brake system.

– If the brake fluid level falls below the MIN mark, this indicates a leakage in the brake system or worn-out brake linings.

Check the brake system and do not continue riding. (Your authorized KTM workshop will be glad to help.)

Warning

Danger of accidents Reduced braking effect caused by old brake fluid.

– Change the brake fluid of the front and rear brakes according to the service schedule. (Your authorized KTM workshop will

be glad to help.)

400234-10

– Stand the vehicle upright. – Check the brake fluid level in the viewer .

» If an air bubble is visible in viewer :

–

Add rear brake fluid. x ( p. 48)

MAINTENANCE WORK ON CHASSIS AND ENGINE 48

9.58Adding rear brake fluid x

Warning

Danger of accidents Failure of the brake system.

– If the brake fluid level falls below the MIN mark, this indicates a leakage in the brake system or worn-out brake linings.

Check the brake system and do not continue riding. (Your authorized KTM workshop will be glad to help.)

Warning

Skin irritation Brake fluid can cause skin irritation on contact.

Warning

Danger of accidents Reduced braking effect caused by old brake fluid.

– Change the brake fluid of the front and rear brakes according to the service schedule. (Your authorized KTM workshop will

be glad to help.)

Warning

Environmental hazard Hazardous substances cause environmental damage.

– Oil, grease, filters, fuel, cleaners, brake fluid, etc., should be disposed of as stipulated in applicable regulations.

Info

– Stand the vehicle upright. – Remove screw cap  with membrane  and the O-ring. – Add brake fluid to level .

Brake fluid DOT 4 / DOT 5.1 ( p. 94)

– Mount the screw cap with the membrane and the O-ring.

Info

400233-10

9.59Checking the rear brake linings

Clean up overflowed or spilt brake fluid immediately with water.

Warning

Danger of accidents Reduced braking efficiency caused by worn brake linings.

– Change worn brake linings immediately. (Your authorized KTM workshop will be glad to help.)

– Check the brake linings for minimum thickness .

400238-10

Minimum thickness  ≥ 1 mm (≥ 0.04 in)

» If the minimum thickness is less than specified:

–

Change the rear brake linings. x ( p. 50)

– Check the brake linings for damage and cracking.

» If damage or cracking is visible:

–

Change the rear brake linings. x ( p. 50)

MAINTENANCE WORK ON CHASSIS AND ENGINE 49

9.60Removing the rear brake linings x

Warning

Danger of accident Brake system failure.

– Maintenance work and repairs must be carried out professionally. (Your authorized KTM workshop will be glad to help.)

– Press the brake caliper onto the brake disc by hand in order to push back the brake

piston.

Info

Make sure when pushing back the brake piston that you do not press the brake caliper against the spokes.

– Remove locking split pins , withdraw bolt , and take out the brake linings. – Clean the brake caliper and brake caliper support.

400236-10

9.61Installing the rear brake linings x

Warning

Danger of accidents Reduced braking efficiency due to oil or grease on the brake discs.

– Always keep the brake discs free of oil and grease, and clean them with brake cleaner when necessary.

Warning

Danger of accidents Reduced braking efficiency due to use of non-approved brake linings.

– Brake linings available from accessory suppliers are often not tested and approved for use on KTM vehicles. The construc-

– Check the brake discs. ( p. 42) – Check that leaf spring  in the brake caliper and sliding plate  in the brake

caliper support are seated correctly.

Info

The arrow on the leaf spring points in the rotation direction of the brake disc.

500122-10

– Insert the brake linings, insert bolt , and mount locking split pins .

Info

Make sure that the decoupling plate  is mounted on the piston side of the brake lining.

– Operate the foot brake lever repeatedly until the brake linings lie on the brake disc

and there is a pressure point.

400237-10

MAINTENANCE WORK ON CHASSIS AND ENGINE 50

9.62Changing the rear brake linings x

Warning

Skin irritation Brake fluid can cause skin irritation on contact.

Warning

Danger of accidents Reduced braking effect caused by old brake fluid.

– Change the brake fluid of the front and rear brakes according to the service schedule. (Your authorized KTM workshop will

be glad to help.)

Warning

Environmental hazard Hazardous substances cause environmental damage.

– Oil, grease, filters, fuel, cleaners, brake fluid, etc., should be disposed of as stipulated in applicable regulations.

Info

9.63Removing the front wheel x

400233-10

–

Remove the rear brake linings. x ( p. 49)

– Stand the vehicle upright. – Remove screw cap  with membrane  and the O-ring. – Press the brake piston back to its basic position and make sure that no brake fluid

overflows from the brake fluid reservoir.

–

Install the rear brake linings. x ( p. 49)

– Add brake fluid to level .

Brake fluid DOT 4 / DOT 5.1 ( p. 94)

– Mount the screw cap with the membrane and the O-ring.

Info

Clean up overflowed or spilt brake fluid immediately with water.

– Jack up the motorcycle. ( p. 26) – Press the brake caliper onto the brake disc by hand in order to push back the brake

pistons.

Info

Make sure when pushing back the brake pistons that you do not press the brake caliper against the spokes.

B00055-10

500084-10

– Remove screw . – Loosen screws .

MAINTENANCE WORK ON CHASSIS AND ENGINE 51

– Holding the front wheel, withdraw the wheel spindle. Take the front wheel out of

the fork.

Info

Do not pull the hand brake lever when the front wheel is removed. Always lay the wheel down in such a way that the brake disc is not damaged.

500085-10

– Remove spacers .

500086-10

9.64Installing the front wheel x

Warning

Danger of accidents Reduced braking efficiency due to oil or grease on the brake discs.

– Always keep the brake discs free of oil and grease, and clean them with brake cleaner when necessary.

– Clean and grease shaft seal rings  and bearing surface  of the spacers.

Long-life grease ( p. 96)

– Insert the spacers.

500086-11

– Lift the front wheel into the fork, position it, and insert the wheel spindle. – Mount and tighten screw .

Guideline

Screw, front wheel spindle M24x1.5 45 Nm

– Operate the hand brake lever several times until the brake linings are lying correctly

on the brake disc.

500084-11

– Remove the motorcycle from the work stand. ( p. 26) – Pull the front wheel brake and push down hard on the fork several times to align

the fork legs.

– Tighten screws .

Guideline

Screw, fork stub M8 15 Nm

(33.2 lbf ft)

(11.1 lbf ft)

MAINTENANCE WORK ON CHASSIS AND ENGINE 52

9.65Removing the rear wheel x

– Jack up the motorcycle. ( p. 26) – Press the brake caliper onto the brake disc by hand in order to push back the brake

piston.

Info

Make sure when pushing back the brake piston that you do not press the brake caliper against the spokes.

– Remove nut . – Remove chain adjuster . Withdraw wheel spindle  only enough to allow the rear

wheel to be pushed forward.

– Push the rear wheel forward as far as possible. Remove the chain from the rear

sprocket.

– Holding the rear wheel, withdraw the wheel spindle. Take the rear wheel out of the

swingarm.

Info

Do not operate the foot brake when the rear wheel is removed. Always lay the wheel down in such a way that the brake disc is not damaged.

400258-10

– Remove spacers .

400260-11

9.66Installing the rear wheel x

Warning

Danger of accidents Reduced braking efficiency due to oil or grease on the brake discs.

– Always keep the brake discs free of oil and grease, and clean them with brake cleaner when necessary.

– Clean and grease shaft seal rings  and bearing surface  of the spacers.

Long-life grease ( p. 96)

– Insert the spacers.

400260-10

400259-10

– Lift the rear wheel into the swing arm, position it, and insert wheel spindle . – Apply the chain.

MAINTENANCE WORK ON CHASSIS AND ENGINE 53

– Position chain adjuster . Mount nut , but do not tighten it yet. – Check the chain tension. ( p. 40) – Make sure that chain adjusters  are fitted correctly on adjusting screws . – Tighten nut .

Guideline

Nut, rear wheel spindle M20x1.5 80 Nm (59 lbf ft)

Info

The wide adjustment range of the chain adjusters (32 mm) enables different secondary transmissions with the same chain length. Chain adjusters  can be turned by 180°.

– Operate the foot brake lever repeatedly until the brake linings lie on the brake disc

and there is a pressure point.

– Remove the motorcycle from the work stand. ( p. 26)

400225-12

9.67Checking the tire condition

Info

Only mount tires approved and/or recommended by KTM. Other tires could have a negative effect on handling characteristics. The type, condition and air pressure of the tires all have an important impact on the handling characteristics of the motorcycle. The front and rear wheels must be mounted with tires with similar profiles. Worn tires have a negative effect on handling characteristics, especially on wet surfaces.

– Check the front and rear tires for cuts, run-in objects and other damage.

» If the tires exhibit cuts, run-in objects or other damage:

– Change the tire.

– Check the depth of the tread.

Info

Note local national regulations concerning the minimum tread depth.

400602-10

Minimum tread depth ≥ 2 mm (≥ 0.08 in)

» If the tread depth is less than the minimum permissible depth:

– Change the tire.

– Check the age of the tires.

Info

The tire's date of manufacture is usually part of the tire markings and is indicated by the last four digits of the DOT marking. The first two digits indicate the week of manufacture and the last two digits the year of manufacture. KTM recommends that the tires are changed at the latest after 5 years, regardless of the actual state of wear.

» If the tires are older than five years:

– Change the tire.

MAINTENANCE WORK ON CHASSIS AND ENGINE 54

9.68Checking the tire air pressure

Info

Low tire air pressure leads to abnormal wear and overheating of the tire. Correct tire air pressure ensures optimal riding comfort and maximum tire service life.

– Remove the dust cap. – Check the tire air pressure when the tires are cold.

Tire air pressure off road

Front 1.0 bar (15 psi) Rear 1.0 bar (15 psi)

» If the tire pressure does not meet specifications:

– Correct the tire pressure.

400695-01

9.69Checking the spoke tension

Warning

Danger of accidents Instable handling due to incorrect spoke tension.

– Ensure that the spoke tension is correct. (Your authorized KTM workshop will be glad to help.)

– Mount the dust cap.

Info

A loose spoke causes wheel imbalance and rapidly leads to more loose spokes. If the spokes are too tight, they can break due to local overload. Check the spoke tension regularly, especially on a new motorcycle.

– Briefly strike each spoke with the tip of a screwdriver.

Info

The tone frequency depends on the length of the spoke and the spoke diameter. If you hear different tone frequencies from different spokes of equal length and diameter, this is an indication of different spoke tensions.

You should hear a high note.

400694-01

» If the spoke tension varies:

–

Correct the spoke tension. x

– Check the spoke torque.

Guideline

Spoke nipple, front wheel M4.5 5… 6 Nm (3.7…

Spoke nipple, rear wheel M5 5… 6 Nm (3.7…

Torque wrench with various accessories in set (58429094000)

4.4 lbf ft)

9.70Ignition curve plug connection

B00029-10

Plug connection  is located in front of the fuel tank on the left side of the frame.

Possible states

• Soft – The plug connection is disconnected to achieve better rideability.

• Performance – The plug connection is connected to achieve better performance.

MAINTENANCE WORK ON CHASSIS AND ENGINE 55

00011

00044

0033

9.71Changing the ignition curve

Change the ignition curve from Performance to Soft.

– Disconnect plug connection . (Figure B00029-10 p. 54)

Soft – better rideability

Change the ignition curve from Soft to Performance.

– Connect plug connection . (Figure B00029-10 p. 54)

Performance – better performance

9.72Engine characteristic - auxiliary spring (250 SX)

The auxiliary spring is located on the right side of the engine below the water pump cover.

Possible states

• Auxiliary spring with yellow marking – Auxiliary spring mounted at the factory with medium tuning (standard) for good rideability.

• Auxiliary spring with green marking – Auxiliary spring contained in the separate enclosure for softer performance.

• Auxiliary spring with red marking – Auxiliary spring contained in the separate enclosure for more aggressive performance.

B00056-10

The engine characteristic can be influenced by different spring strengths of the auxiliary spring .

9.73Engine characteristic - adjusting the auxiliary spring x (250 SX)

Warning

Danger of burns Some vehicle components get very hot when the vehicle is in use.

– Do not touch hot components such as exhaust system, radiator, engine, shock absorber and brakes. Allow these compo-

nents to cool down before starting work on them.

– Tilt the motorcycle approx. 45º to the left and fix it in this position. – Remove screws .

B00057-10

– Take locking cap , adjusting spring , auxiliary spring  and spring insert  out

of the clutch cover.

– Pull both springs out of the spring insert.

B00056-11

B00058-10

– Mount the required auxiliary spring  and adjusting spring  and slide them into

the clutch cover together.

Auxiliary spring with yellow marking (54837072300) Auxiliary spring with green marking (54837072100) Auxiliary spring with red marking (54837072000)

The notch in the spring insert  engages in the angle lever.

Info

It is important that screw  is not turned as this would be detrimental to the engine characteristic.

MAINTENANCE WORK ON CHASSIS AND ENGINE 56

– Check the O-ring in the locking cap. – Position the locking cap. – Mount and tighten the screws.

Guideline

Remaining screws, engine M5 6 Nm (4.4 lbf ft)

9.74Removing the seat

– Remove screw . Lift up the seat at the rear, pull it back and then remove from

above.

500080-10

9.75Mounting the seat

– Hook in the front of the seat at the collar bushing of the fuel tank, lower at the rear

and simultaneously push forward.

– Make sure that the seat is correctly locked in. – Mount and tighten the screw of the seat fixing.

Guideline

Remaining screws, chassis M6 10 Nm (7.4 lbf ft)

500068-01

9.76Removing the fuel tank x

Danger

Fire hazard Fuel is highly flammable.

– Never refuel the vehicle near open flames or burning cigarettes, and always switch off the engine first. Be careful that no

fuel is spilt, especially on hot vehicle components. Clean up spilt fuel immediately.

– Fuel in the fuel tank expands when warm and can escape if the tank is overfilled. See the notes on refueling.

Warning

Danger of poisoning Fuel is poisonous and a health hazard.

– Avoid contact between fuel and skin, eyes and clothing. Do not inhale fuel vapors. If fuel gets into your eyes, rinse immedi-

ately with water and contact a doctor. Wash affected skin areas immediately with soap and water. If fuel is swallowed, contact a doctor immediately. Change clothing that has come into contact with fuel. Store fuel in a suitable canister according to regulations and keep it out of the reach of children.

– Remove the seat. ( p. 56) – Close the fuel tap. – Pull off the fuel hose.

Info

Remaining fuel may run out of the fuel hose.

B00031-10

– Remove screws  with the collar sleeve.

MAINTENANCE WORK ON CHASSIS AND ENGINE 57

– Remove screw  with the collar sleeve. – Remove the tube from the fuel tank vent line.

B00033-10

– Pull both spoilers sideways off of radiator bracket  and lift off the fuel tank.

B00032-10

9.77Installing the fuel tank x

Danger

Fire hazard Fuel is highly flammable.

– Never refuel the vehicle near open flames or burning cigarettes, and always switch off the engine first. Be careful that no

fuel is spilt, especially on hot vehicle components. Clean up spilt fuel immediately.

– Fuel in the fuel tank expands when warm and can escape if the tank is overfilled. See the notes on refueling.

Warning

Danger of poisoning Fuel is poisonous and a health hazard.

– Avoid contact of the fuel with skin, eyes and clothing. Do not inhale fuel vapors. If fuel gets into your eyes, rinse imme-

– Position the fuel tank and fit the two spoilers to the sides of the radiator bracket. – Make sure that no cables are trapped or damaged.

B00032-01

– Mount the fuel tank vent hose. – Mount and tighten  with the collar sleeve.

Guideline

Remaining screws, chassis M6 10 Nm (7.4 lbf ft)

B00033-11

MAINTENANCE WORK ON CHASSIS AND ENGINE 58

– Mount and tighten screws  with the collar sleeve.

Guideline

Remaining screws, chassis M6 10 Nm (7.4 lbf ft)

– Connect the fuel hose. – Mount the seat. ( p. 56)

B00031-11

9.78Cooling system

(125 SX, 150 SX)

Water pump  in the engine circulates the coolant. The pressure resulting from the warming of the cooling system is regulated by a valve in radiator cap . This ensures that operating the vehicle at the specified coolant temperature will not result in a risk of malfunctions.

120 °C (248 °F)

Cooling is effected by the air stream. The lower the speed, the less the cooling effect. Dirty cooling fins also reduce the

B00043-10

cooling effect.

(250 SX)

120 °C (248 °F)

Cooling is effected by the air stream. The lower the speed, the less the cooling effect. Dirty cooling fins also reduce the

B00044-10

9.79Checking the antifreeze and coolant level

cooling effect.

Warning

Danger of scalding During motorcycle operation, the coolant gets very hot and is under pressure.

– Do not remove the radiator cap, radiator hoses or other cooling system components when the engine is hot. Allow the

engine and cooling system to cool down. In case of scalding, rinse immediately with lukewarm water.

Warning

Danger of poisoning Coolant is poisonous and a health hazard.

– Avoid contact between coolant and skin, eyes and clothing. If fuel gets into your eyes, rinse immediately with water and

contact a doctor. Wash affected skin areas immediately with soap and water. If coolant is swallowed, contact a doctor immediately. Change clothes that have come into contact with coolants. Keep coolant out of the reach of children.

Condition

The engine is cold.

– Stand the motorcycle upright on a horizontal surface. – Remove the radiator cap. – Check the coolant antifreeze.

400243-10

−25… −45 °C (−13… −49 °F)

» If the coolant antifreeze does not meet specifications:

– Correct the coolant antifreeze.

– Check the coolant level in the radiator.

Coolant level  above the radiator fins. 10 mm (0.39 in)

» If the level of the coolant does not meet specifications:

MAINTENANCE WORK ON CHASSIS AND ENGINE 59

– Correct the coolant level.

Alternative 1

Coolant ( p. 94)

Alternative 2

Coolant (mixed ready to use) ( p. 94)

– Mount the radiator cap.

9.80Checking the coolant level

Warning

Danger of scalding During motorcycle operation, the coolant gets very hot and is under pressure.

– Do not remove the radiator cap, radiator hoses or other cooling system components when the engine is hot. Allow the

engine and cooling system to cool down. In case of scalding, rinse immediately with lukewarm water.

Warning

Danger of poisoning Coolant is poisonous and a health hazard.

– Avoid contact between coolant and skin, eyes and clothing. If fuel gets into your eyes, rinse immediately with water and

Condition

The engine is cold.

– Stand the motorcycle upright on a horizontal surface. – Remove the radiator cap. – Check the coolant level in the radiator.

Coolant level  above the radiator fins. 10 mm (0.39 in)

» If the level of the coolant does not meet specifications:

– Correct the coolant level.

Alternative 1

400243-10

Coolant ( p. 94)

Alternative 2

Coolant (mixed ready to use) ( p. 94)

– Mount the radiator cap.

9.81Draining the coolant x

Warning

Danger of scalding During motorcycle operation, the coolant gets very hot and is under pressure.

– Do not remove the radiator cap, radiator hoses or other cooling system components when the engine is hot. Allow the

engine and cooling system to cool down. In case of scalding, rinse immediately with lukewarm water.

Warning

Danger of poisoning Coolant is poisonous and a health hazard.

– Avoid contact between coolant and skin, eyes and clothing. If fuel gets into your eyes, rinse immediately with water and

Condition

The engine is cold.

– Stand the motorcycle upright. – Place a suitable container under the water pump cover.

MAINTENANCE WORK ON CHASSIS AND ENGINE 60

(125 SX, 150 SX)

– Remove screw . Remove radiator cap . – Completely drain the coolant. – Mount screw  with a new seal ring and tighten it.

Guideline

Drain plug, water pump cover M10x1 15 Nm

(11.1 lbf ft)

B00043-11

(250 SX)

– Remove screw . Remove radiator cap . – Completely drain the coolant. – Mount screw  with a new seal ring and tighten it.

Guideline

Drain plug, water pump cover M10x1 15 Nm

(11.1 lbf ft)

B00044-11

9.82Refilling with coolant x

Warning

Danger of poisoning Coolant is poisonous and a health hazard.

– Avoid contact between coolant and skin, eyes and clothing. If fuel gets into your eyes, rinse immediately with water and

(125 SX, 150 SX)

– Make sure that screw  is tightened.

B00071-10

(250 SX)

– Make sure that screw  is tightened.

B00072-10

B00073-10

– Stand the motorcycle upright. – Fill the radiator completely with coolant.

Coolant 1.2 l (1.3 qt.) Coolant ( p. 94)

Coolant (mixed ready to use) ( p. 94)

– Mount radiator cap . – Run the engine until it is warm. – Check the coolant level. ( p. 59)

MAINTENANCE WORK ON CHASSIS AND ENGINE 61

9.83Removing the main silencer

Warning

Danger of burns The exhaust system gets very hot when the vehicle is driven.

– Allow the exhaust system to cool down. Do not touch hot components.

– Remove screws . – Pull the main silencer off of the manifold at the rubber sleeve .

B00036-10

9.84Installing the main silencer

– Mount the main silencer with rubber sleeve . – Mount and tighten screws .

Guideline

Remaining screws, chassis M6 10 Nm (7.4 lbf ft)

B00036-11

9.85Glass fiber yarn filling of main silencer

The main silencer is filled with glass fiber yarn . Over a period, the fibers of the insulating material vanish into the air, and the silencer "burns out". Not only is the noise level higher, the performance characteristic changes.

B00063-10

9.86Changing the glass fiber yarn filling of the main silencer x

–

Remove the glass fiber yarn filling of the main silencer. x ( p. 62)

–

Install the glass fiber yarn filling of the main silencer. x ( p. 62)

B00063-00

MAINTENANCE WORK ON CHASSIS AND ENGINE 62

0033

0022

0033

0044

9.87Removing the glass fiber yarn filling of the main silencer x

Warning

Danger of burns The exhaust system gets very hot when the vehicle is driven.

– Allow the exhaust system to cool down. Do not touch hot components.

– Remove the main silencer. ( p. 61) – Remove nut . – Remove the locking cap and outer tube . – Pull the glass fiber yarn filling  from the inner tube. – Clean the parts that are to be reinstalled.

B00037-10

9.88Installing the glass fiber yarn filling of the main silencer x

– Slide the glass fiber yarn filling  over the inner tube. – Slide the outer tube  over the glass fiber yarn filling.

9.89Removing the air filter box lid

9.90Installing the air filter box lid

B00074-10

B00038-10

Info

Ensure that the O-rings are seated properly.

– Insert locking cap  into the outer tube. – Mount and tighten nut . – Install the main silencer. ( p. 61)

– Pull off the air filter box lid in area  sideways and remove it toward the front.

– Insert the air filter box lid into the rear area  and clip it into the front area .

B00038-11

MAINTENANCE WORK ON CHASSIS AND ENGINE 63

9.91Removing the air filter x

Note

Engine failure Unfiltered intake air has a negative effect on the service life of the engine.

– Never ride the vehicle without an air filter since dust and dirt can get into the engine and result in increased wear.

Warning

Environmental hazard Hazardous substances cause environmental damage.

– Oil, grease, filters, fuel, cleaners, brake fluid, etc., should be disposed of as stipulated in applicable regulations.

– Remove the air filter box lid. ( p. 62) – Detach air filter holder  at the bottom and swing it to one side. Remove the air

filter with the air filter support.

– Remove the air filter from the air filter support.

B00039-10

9.92Installing the air filter x

– Mount the clean air filter onto the air filter support. – Grease the air filter in area .

Long-life grease ( p. 96)

301262-10

– Put in both parts together, position them, and fix them with air filter holder .

Info

If the air filter is not correctly mounted, dust and dirt can penetrate into the engine and can cause damage.

– Install the air filter box lid. ( p. 62)

B00039-10

9.93Cleaning the air filter x

Warning

Environmental hazard Hazardous substances cause environmental damage.

– Oil, grease, filters, fuel, cleaners, brake fluid, etc., should be disposed of as stipulated in applicable regulations.

Info

Do not clean the air filter with fuel or petroleum since these substances attack the foam.

–

Remove the air filter. x ( p. 63)

– Wash the air filter thoroughly in special cleaning liquid and allow it to dry properly.

Air filter cleaner ( p. 96)

Info

Only press the air filter to dry it; never wring it out.

MAINTENANCE WORK ON CHASSIS AND ENGINE 64

– Oil the dry air filter with a high quality filter oil.

Oil for foam air filter ( p. 96)

– Clean the air filter box. – Check the carburetor connection boot for damage and tightness.

–

Install the air filter. x ( p. 63)

9.94Adjusting the basic position of the clutch lever

(125 SX, 150 SX)

– Adjust the basic setting of the clutch lever to your hand size by turning adjust-

ing screw .

Info

Turn the adjusting screw counterclockwise to increase the distance between the clutch lever and the handlebar. Turn the adjusting screw clockwise to decrease the distance between the clutch lever and the handlebar.

B00001-11

(250 SX)

– Adjust the basic setting of the clutch lever to your hand size by turning adjust-

The range of adjustment is limited. Turn the adjusting screw by hand only, and do not apply any force. Do not make any adjustments while riding!

ing screw .

B00009-11

9.95Checking the fluid level of the hydraulic clutch

Info

The fluid level rises with increasing wear of the clutch lining discs.

(125 SX, 150 SX)

– Move the clutch fluid reservoir mounted on the handlebar to a horizontal posi-

tion.

– Remove screws . – Remove cover  with membrane . – Check the fluid level.

Fluid level under top edge of container

400245-10

» If the level of the fluid does not meet specifications:

– Correct the fluid level of the hydraulic clutch.

Info

Turn the adjusting screw counterclockwise to decrease the distance between the clutch lever and the handlebar. Turn the adjusting screw clockwise to increase the distance between the clutch lever and the handlebar. The range of adjustment is limited. Turn the adjusting screw by hand only, and do not apply any force. Do not make any adjustments while riding!

4 mm (0.16 in)

B00040-10

Hydraulic fluid (15) ( p. 94)

– Position the cover with the membrane. Mount and tighten the screws.

(250 SX)

– Move the clutch fluid reservoir mounted on the handlebar to a horizontal posi-

tion.

– Remove screws . – Remove cover  with membrane . – Check the fluid level.

Fluid level under top edge of con-

4 mm (0.16 in)

tainer

MAINTENANCE WORK ON CHASSIS AND ENGINE 65

» If the level of the fluid does not meet specifications:

– Correct the fluid level of the hydraulic clutch.

Brake fluid DOT 4 / DOT 5.1 ( p. 94)

– Position the cover with the membrane. Mount and tighten the screws.

9.96Changing the hydraulic clutch fluid x

Warning

Environmental hazard Hazardous substances cause environmental damage.

– Oil, grease, filters, fuel, cleaners, brake fluid, etc., should be disposed of as stipulated in applicable regulations.

(125 SX, 150 SX)

– Move the clutch fluid reservoir mounted on the handlebar to a horizontal posi-

tion.

– Remove screws . – Remove cover  with membrane .

400245-10

– Fill bleeding syringe  with the appropriate hydraulic fluid.

B00041-10

400247-10

Bleed syringe (50329050000) Hydraulic fluid (15) ( p. 94)

– On the slave cylinder, remove bleeder screw  and mount bleeding syringe .

– Inject the liquid into the system until it escapes from hole  of the master

cylinder without bubbles.

– To prevent overflow, drain fluid occasionally from the master cylinder reservoir. – Remove the bleeding syringe. Mount and tighten the bleeder screw. – Correct the fluid level of the hydraulic clutch.

Guideline

Fluid level under top edge of con-

4 mm (0.16 in)

tainer

– Position the cover with the membrane. Mount and tighten the screws.

(250 SX)

– Move the clutch fluid reservoir mounted on the handlebar to a horizontal posi-

tion.

– Remove screws . – Remove cover  with membrane .

B00040-10

B00064-10

– Fill bleeding syringe  with the appropriate hydraulic fluid.

Bleed syringe (50329050000) Brake fluid DOT 4 / DOT 5.1 ( p. 94)

– On the slave cylinder, remove bleeder screw  and mount bleeding syringe .

MAINTENANCE WORK ON CHASSIS AND ENGINE 66

000AA

– Inject the liquid into the system until it escapes from hole  of the master

cylinder without bubbles.

Guideline

B00042-10

9.97Checking the basic position of the shift lever

– Sit on the vehicle in the riding position and determine the distance between the

Fluid level under top edge of container

– Position the cover with the membrane. Mount and tighten the screws.

upper edge of your boot and shift lever .

4 mm (0.16 in)

Distance between shift lever and upper edge of boot

» If the distance does not meet specifications:

400692-10

9.98Adjusting the basic position of the shift lever x

– Remove screw  and remove shift lever .

B00065-10

– Clean gear teeth  of the shift lever and shift shaft. – Mount the shift lever on the shift shaft in the required position and engage the

gearing.

10… 20 mm (0.39… 0.79 in)

–

Adjust the basic position of the shift lever. x ( p. 66)

Info

When positioning the shift lever, ensure that there is sufficient distance to the adjacent components.

9.99Carburetor

B00066-10

B00048-11

– Mount and tighten the screw.

Guideline

Screw, shift lever M6 14 Nm

Loctite®243™

(10.3 lbf ft)

The idle setting of the carburetor has a big influence on the starting behavior, idling stability and the response to opening of the throttle. An engine with a correctly set idle speed is easier to start than if the idle is set wrongly.

Info

The carburetor and its components are subject to increased wear caused by engine vibration. Wear can result in malfunctioning.

The carburetor factory settings are as follows.

(125 SX, 150 SX)

Altitude above sea level 500 m (1,640 ft) Ambient temperature 20 °C (68 °F) Super unleaded gasoline, mixed with 2-stroke engine oil (1:40) ( p. 95)

MAINTENANCE WORK ON CHASSIS AND ENGINE 67

000DD

BB 0

(250 SX)

Altitude above sea level 500 m (1,640 ft) Ambient temperature 20 °C (68 °F) Super unleaded gasoline, mixed with 2-stroke engine oil (1:60) ( p. 95)

The idle speed is adjusted with adjustment screw . The idle mixture is adjusted with idle adjusting screw .

Idle range A

Operation with the throttle slide closed. The range is influenced by the adjustment screw  and the idle air adjusting screw .

Transition range B

Behavior of the engine when the throttle slide is opened. This range is influenced by the idling jet and the shape of the throttle slide. If the engine stutters and smokes heavily when the throttle slide is opened despite a good idle and part-load setting, and if it achieves full power abruptly at high engine speeds, the carburetor setting is too rich, the float level is too high or the float needle

500282-01

valve is not tight.

Part-load range C

Operation with the throttle slide partially opened. This range is influenced by the jet needle (shape and position). In the lower range, the engine tuning is influenced by the idle setting and in the upper range by the main jet. If the engine stutters when accelerating with the throttle slide partially opened, the jet needle must be lowered by one step. If the engine knocks during acceleration when it reaches full power engine speed, the jet needle must be raised. If the behavior described above is exhibited while in idle or just above idle, the idle system must be run leaner if there is stuttering and richer if there is knocking.

Full-load range D

Operation with the throttle slide fully opened (full throttle). This range is influenced by the main jet and jet needle. If the insulator of a new spark plug is very light or white after riding full throttle for a short period, or if the engine knocks, a larger main jet needs to be used. If the insulator is dark brown or sooty, a smaller main jet needs to be used.

9.100Carburetor - adjusting the idle speed x

B00048-11

– Screw in idle air adjusting screw  all the way and turn it to the specified basic

position. Guideline

Idle air adjusting screw (125 SX, 150 SX)

Open 1.5 turns

Idle air adjusting screw (250 SX)

Open 1.0 turn

– Run the engine until warm.

Guideline

Warm-up time ≥ 5 min

Danger

Danger of poisoning Exhaust gases are poisonous and inhaling them may

result in unconsciousness and/or death.

– When running the engine, always make sure there is sufficient ventila-

tion, and do not start or run the engine in an enclosed space without an effective exhaust extraction system.

– Adjust the idle speed with adjusting screw .

Guideline

Choke function deactivated – The choke lever is pushed in to the stop. ( p. 11) Idle speed 1,400… 1,500 rpm

– Turn idle air adjusting screw  slowly in a clockwise direction until the idle speed

begins to fall.

– Note the position and turn the idle air adjusting screw slowly counterclockwise until

the idle speed falls again.

MAINTENANCE WORK ON CHASSIS AND ENGINE 68

– Adjust to the point between these two positions with the highest idle speed.

Info

If there is a large engine speed rise, reduce the idle speed to a normal level and repeat the above steps. If the procedure described here does not lead to satisfactory results, the cause may be a wrongly dimensioned idling jet. If you can turn the idle air adjusting screw to the end without any change of engine speed, you need to install a smaller idling jet. After changing the idling jet, repeat the adjusting steps from the beginning. Following extreme air temperature or altitude changes, adjust the idle speed again.

9.101Emptying the carburetor float chamber x

Danger

Fire hazard Fuel is highly flammable.

– Never refuel the vehicle near open flames or burning cigarettes, and always switch off the engine first. Be careful that no

fuel is spilt, especially on hot vehicle components. Clean up spilt fuel immediately.

– Fuel in the fuel tank expands when warm and can escape if the tank is overfilled. See the notes on refueling.

Warning

Danger of poisoning Fuel is poisonous and a health hazard.

– Avoid contact between fuel and skin, eyes and clothing. Do not inhale fuel vapors. If fuel gets into your eyes, rinse immedi-

Warning

Environmental hazard Improper handling of fuel is a danger to the environment.

– Do not allow fuel to get into the ground water, the ground, or the sewage system.

Info

Carry out this work with a cold engine. Water in the float chamber results in malfunctioning.

– Turn handle  of the fuel tap to the OFF position. (Figure B00003-10 p. 11)

No more fuel flows from the tank to the carburetor.

– Place a cloth beneath the carburetor to soak up emerging fuel. – Remove plug . – Completely drain the fuel. – Mount and tighten the plug.

B00047-10

9.102Checking the gear oil level

Info

The gear oil level must be checked when the engine is cold.

– Stand the motorcycle upright on a horizontal surface.

MAINTENANCE WORK ON CHASSIS AND ENGINE 69

(125 SX, 150 SX)

– Remove gear oil level check screw . – Check the gear oil level.

A small amount of gear oil should flow out of the hole.

» If no gear oil flows out:

–

Add gear oil. x ( p. 70)

– Mount and tighten the gear oil level check screw.

B00049-10

B00050-10

Guideline

Screw, gear oil level check M6 10 Nm

(250 SX)

– Remove gear oil level check screw . – Check the gear oil level.

A small amount of gear oil should flow out of the hole.

» If no gear oil flows out:

–

Add gear oil. x ( p. 70)

– Mount and tighten the gear oil level check screw.

Guideline

Screw, gear oil level check M6 10 Nm

(7.4 lbf ft)

9.103Changing the gear oil x

–

Drain the gear oil. x ( p. 69)

400721-01

–

Refill with gear oil. x ( p. 70)

400722-01

9.104Draining the gear oil x

Warning

Danger of scalding Engine oil and gear oil get very hot when the motorcycle is ridden.

– Wear appropriate protective clothing and safety gloves. In case of burns, rinse immediately with lukewarm water.

Warning

Environmental hazard Hazardous substances cause environmental damage.

– Oil, grease, filters, fuel, cleaners, brake fluid, etc., should be disposed of as stipulated in applicable regulations.

Info

Drain the gear oil only when the engine is warm.

MAINTENANCE WORK ON CHASSIS AND ENGINE 70

– Place the motorcycle on a level surface. – Place a suitable container under the engine.

(125 SX, 150 SX)

– Remove the gear oil drain plug with magnet . – Remove the gear oil drain plug . – Completely drain the gear oil. – Clean the gear oil drain plug thoroughly. – Clean the sealing area on the engine. – Mount the gear oil drain plug with magnet  and the seal ring and tighten it.

B00051-10

B00052-10

Guideline

Gear oil drain plug with magnet M12x1.5 20 Nm

(14.8 lbf ft)

– Mount gear oil drain plug  with the seal ring and tighten it.

Guideline

Gear oil drain plug M10x1 15 Nm

(11.1 lbf ft)

(250 SX)

– Remove the gear oil drain plug with magnet . – Completely drain the gear oil. – Thoroughly clean the gear oil drain plug with a magnet. – Clean the sealing area on the engine. – Mount the gear oil drain plug with magnet  and the seal ring and tighten it.

Guideline

Gear oil drain plug with magnet M12x1.5 20 Nm

(14.8 lbf ft)

9.105Refilling with gear oil x

Info

Too little gear oil or poor-quality oil results in premature wear of the transmission.

– Remove screw cap  and fill up gear oil.

Gear oil 0.70 l (0.74 qt.) Engine oil (15W/50) ( p. 94)

– Mount and tighten the screw cap.

Danger

Danger of poisoning Exhaust gases are poisonous and inhaling them may

result in unconsciousness and/or death.

– When running the engine, always make sure there is sufficient ventila-

B00053-10

tion, and do not start or run the engine in an enclosed space without an effective exhaust extraction system.

– Start the engine and check that it is oil-tight. – Check the gear oil level. ( p. 68)

9.106Adding gear oil x

Info

Too little gear oil or poor-quality oil results in premature wear of the transmission. The gear oil must be added when the engine is cold.

– Place the motorcycle on a level surface.

MAINTENANCE WORK ON CHASSIS AND ENGINE 71

(125 SX, 150 SX)

– Remove gear oil level check screw .

B00049-10

(250 SX)

– Remove gear oil level check screw .

B00050-10

– Remove screw cap . – Add gear oil until it flows out of the hole of the gear oil level check screw.

B00053-11

Engine oil (15W/50) ( p. 94)

– Mount and tighten the gear oil level check screw.

Guideline

Screw, gear oil level check M6 10 Nm (7.4 lbf ft)

– Mount and tighten screw cap .

Danger

Danger of poisoning Exhaust gases are poisonous and inhaling them may

result in unconsciousness and/or death.

– When running the engine, always make sure there is sufficient ventila-

tion, and do not start or run the engine in an enclosed space without an effective exhaust extraction system.

– Start the engine and check that it is oil-tight.

TROUBLESHOOTING 72

Faults Possible cause Action

Engine turns but does not start Operating error – Go through the steps of starting the engine.

( p. 19)

Motorcycle was out of use for a long time and there is old fuel in the float chamber

Fuel feed interrupted – Check the fuel tank breather.

Engine flooded – Clean and dry the spark plug, or change it if

Spark plug oily or wet – Clean and dry the spark plug, or change it if

Electrode distance (plug gap) of spark plug too wide

Fault in ignition system – Short circuit cable in cable harness

frayed, short circuit button defective Socket connector or ignition coil is

loose or oxidized Water in carburetor or jets blocked – Check/set the carburetor components.

Engine has no idle Idling jet blocked – Check/set the carburetor components.

Adjusting screws on carburetor distorted

Spark plug defective – Change the spark plug. Ignition system defective –

Engine does not speed up Carburetor running over because float

needle dirty or worn Loose carburetor jets – Check/set the carburetor components. Fault in ignition system –

Engine has too little power Fuel feed interrupted – Check the fuel tank breather.

Air filter very dirty – Exhaust system leaky, deformed or

too little glass fiber yarn filling in main silencer

Fault in ignition system – Diaphragm or reed valve housing

damaged

Engine stalls or is popping into the carburetor

Engine overheats Too little coolant in cooling system – Check the cooling system for leakage.

Lack of fuel – Turn handle  of the fuel tap to the ON posi-

Engine takes in bad air – Check the intake flange and carburetor for

Socket connector or ignition coil is loose or oxidized

Too little air stream – Switch off engine when stationary.

–

Empty the carburetor float chamber. x

( p. 68)

– Clean the fuel tap. – Check/set the carburetor components.

necessary.

– Adjust the plug gap.

Guideline

(125 SX, 150 SX)

Spark plug electrode gap

0.60 mm (0.0236 in)

(250 SX)

Spark plug electrode gap

0.60 mm (0.0236 in)

Check the ignition system. x

–

Check the short circuit button. x

– Clean the plug-in connector and treat it with

contact spray.

–

Carburetor - adjust the idle speed. x

( p. 67)

Check the ignition coil. x

–

Check the spark plug connector. x

– Check/set the carburetor components.

Check the ignition system. x

– Clean the fuel tap.

–

Check/set the carburetor components.

Clean the air filter. x ( p. 63)

– Check exhaust system for damage. – Change the glass fiber yarn filling of the main

silencer. x ( p. 61) Check the ignition system. x

– Check the diaphragm and reed valve housing.

tion. (Figure B00003-10 p. 11)

– Refuel. ( p. 21)

tightness.

– Clean the plug-in connector and treat it with

contact spray.

– Check the coolant level. ( p. 59)

TROUBLESHOOTING 73

Faults Possible cause Action

Engine overheats Radiator fins very dirty – Clean the radiator fins.

Foam formation in cooling system –

Damaged cylinder head or cylinder head gasket

Bent radiator hose – Incorrect ignition point due to loose

stator

White smoke emission (steam in exhaust gas)

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

Damaged cylinder head or cylinder head gasket

pump

Drain the coolant. x ( p. 59)

–

Refill with coolant. x ( p. 60)

– Check the cylinder head or cylinder head gas-

ket.

Change the radiator hose. x

–

Adjust the ignition. x

– Check the cylinder head or cylinder head gas-

ket.

– Check the shaft seal ring and water pump.

CLEANING 74

11.1Cleaning the motorcycle

Note

Material damage Damage and destruction of components by high-pressure cleaning equipment.

– Never clean the vehicle with high-pressure cleaning equipment or a strong water-jet. The excessive pressure can penetrate electri-

cal components, socket connects, throttle cables, and bearings, etc., and can damage or destroy these parts.

Warning

Environmental hazard Hazardous substances cause environmental damage.

– Oil, grease, filters, fuel, cleaners, brake fluid, etc., should be disposed of as stipulated in applicable regulations.

Info

If you clean the motorcycle regularly, its value and appearance are maintained over a long period. Avoid direct sunlight on the motorcycle during cleaning.

– Close off the exhaust system to prevent water from entering. – Remove coarse dirt particles by spraying gently with water. – Spray very dirty areas with a normal motorcycle cleaner and then clean with a soft brush.

Motorcycle cleaner ( p. 96)

Info

Use warm water containing normal motorcycle cleaner and a soft sponge.

– After rinsing the motorcycle with a gentle water spray, allow it to dry thoroughly.

–

Empty the carburetor float chamber. x ( p. 68)

Warning

Danger of accidents Reduced braking due to wet or dirty brakes.

– Clean or dry dirty or wet brakes by riding and braking gently.

– After cleaning, take a short ride until the engine reaches operating temperature.

Info

The heat produced causes water at inaccessible positions in the engine and the brakes to evaporate.

– Push back the protective covers from the handlebar armatures to allow the water to evaporate. – After the motorcycle has cooled off, oil or grease all moving parts and bearings. – Clean the chain. ( p. 39) – Treat bare metal parts (except for brake discs and exhaust system) with anti-corrosion materials.

Cleaning and polishing materials for metal, rubber and plastic ( p. 96)

– Treat all plastic parts and powder-coated parts with a mild cleaning and care product.

Cleaning and polishing materials for metal, rubber and plastic ( p. 96)

– To prevent electrical problems, treat electric contacts and switches with contact spray.

Contact spray ( p. 96)

STORAGE 75

12.1Storage

Warning

Danger of poisoning Fuel is poisonous and a health hazard.

– Avoid contact between fuel and skin, eyes and clothing. Do not inhale fuel vapors. If fuel gets into your eyes, rinse immedi-

Info

If you want to put the motorcycle into storage for a longer period, take the following actions. Before storing the motorcycle, check all parts for function and wear. If service, repairs or replacements are necessary, you should do this during the storage period (less workshop overload). In this way, you can avoid long workshop waiting times at the start of the new season.

– Clean the motorcycle. ( p. 74)

–

Change the gear oil. x ( p. 69)

– Check the antifreeze and coolant level. ( p. 58) – Drain the fuel from the tank into a suitable container.

–

Empty the carburetor float chamber. x ( p. 68)

– Check the tire air pressure. ( p. 54) – Store the vehicle in a dry location that is not subject to large fluctuations in temperature.

Info

KTM recommends jacking up the motorcycle.

– Jack up the motorcycle. ( p. 26) – Cover the vehicle with a tarp or cover that is permeable to air.

Info

Do not use non-porous materials since they prevent humidity from escaping, thus causing corrosion. Avoid running the engine for a short time only. Because the engine will not warm up sufficiently, the water vapor produced during combustion will condense, causing engine parts and the exhaust system to rust.

12.2Putting into operation after storage

– Remove the motorcycle from the work stand. ( p. 26) – Refuel. ( p. 21) – Checks before putting into operation. ( p. 19) – Make a test ride.

TECHNICAL DATA - ENGINE 76

13.1125 SX

Design 1-cylinder 2-stroke engine, water-cooled, with reed intake and

exhaust control Displacement 124.8 cm³ (7.616 cu in) Stroke 54.5 mm (2.146 in) Bore 54 mm (2.13 in) 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) 43.5 mm (1.713 in) Primary transmission 23:73 Clutch Multidisc clutch in oil bath/hydraulically activated Gearbox 6-gear, claw shifted Transmission ratio

1st gear 13:32 2nd gear 15:30 3rd gear 17:28 4th gear 20:28 5th gear 19:23

6th gear 22:24 Ignition Kokusan 2K-1 Ignition point (BTDC) 1.4 mm (0.055 in) Spark plug NGK BR9 ECMVX Spark plug electrode gap 0.60 mm (0.0236 in) Starting aid Kickstarter

13.2150 SX

Design 1-cylinder 2-stroke engine, water-cooled, with reed intake and

exhaust control Displacement 143.6 cm³ (8.763 cu in) Stroke 58.4 mm (2.299 in) Bore 56 mm (2.2 in) 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) 43.1 mm (1.697 in) Primary transmission 23:73 Clutch Multidisc clutch in oil bath/hydraulically activated Gearbox 6-gear, claw shifted Transmission ratio

1st gear 13:32 2nd gear 15:30 3rd gear 17:28 4th gear 20:28 5th gear 19:23 6th gear 22:24

TECHNICAL DATA - ENGINE 77

Ignition Kokusan 2K-1 Ignition point (BTDC) 1.4 mm (0.055 in) Spark plug NGK BR9 ECMVX Spark plug electrode gap 0.60 mm (0.0236 in) Starting aid Kickstarter

13.3250 SX

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 5,500 rpm Exhaust valve - end of adjustment with red auxiliary spring 7,000 rpm Exhaust valve - end of adjustment with yellow auxiliary spring 7,500 rpm Exhaust valve - end of adjustment with green auxiliary spring 7,900 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) 47.5 mm (1.87 in) Primary transmission 26:72 Clutch Multidisc clutch in oil bath/hydraulically activated Gearbox 5-gear, claw shifted Transmission ratio

1st gear 14:28 2nd gear 15:24 3rd gear 18:24 4th gear 21:24

5th gear 22:21 Ignition Kokusan - Stator 2K-1 / Rotor 2K-2 Ignition point (BTDC) 1.9 mm (0.075 in) Spark plug NGK BR8 ECM Spark plug electrode gap 0.60 mm (0.0236 in) Starting aid Kickstarter

13.4Capacity - gear oil

Gear oil 0.70 l (0.74 qt.) Engine oil (15W/50) ( p. 94)

13.5Capacity - coolant

Coolant 1.2 l (1.3 qt.) Coolant ( p. 94)

Coolant (mixed ready to use) ( p. 94)

TECHNICAL DATA - ENGINE TIGHTENING TORQUES 78

14.1125 SX, 150 SX

Remaining screws, engine M5 6 Nm (4.4 lbf ft) – Screw, alternator cover M5 5 Nm (3.7 lbf ft) – Screw, exhaust control cover M5 5 Nm (3.7 lbf ft) – Screw, ignition system/stator M5 6 Nm (4.4 lbf ft) Screw, water pump wheel M5 6 Nm (4.4 lbf ft) Remaining screws, engine M6 10 Nm (7.4 lbf ft) – Screw, clutch cover M6 10 Nm (7.4 lbf ft) – Screw, clutch spring M6 10 Nm (7.4 lbf ft) – Screw, engine housing M6 10 Nm (7.4 lbf ft) – Screw, gear oil level check M6 10 Nm (7.4 lbf ft) – Screw, shift lever M6 14 Nm (10.3 lbf ft) Screw, water pump cover M6 10 Nm (7.4 lbf ft) Screw, cylinder head M7 18 Nm (13.3 lbf ft) – Nuts, cylinder base M8 30 Nm (22.1 lbf ft) – Remaining screws, engine M8 25 Nm (18.4 lbf ft) – Screw, kickstarter M8 25 Nm (18.4 lbf ft) Screw, shift drum locating M8 25 Nm (18.4 lbf ft) Remaining screws, engine M10 45 Nm (33.2 lbf ft) – Drain plug, water pump cover M10x1 15 Nm (11.1 lbf ft) – Gear oil drain plug M10x1 15 Nm (11.1 lbf ft) – Nut, rotor M12x1 60 Nm (44.3 lbf ft) – Gear oil drain plug with magnet M12x1.5 20 Nm (14.8 lbf ft) – Spark plug M14x1.25 25 Nm (18.4 lbf ft) – Nut, primary gear M16LHx1.5 130 Nm (95.9 lbf ft) Nut, inner clutch hub M18x1.5 130 Nm (95.9 lbf ft)

Loctite®222

Loctite®243™

14.2250 SX

M5 7 Nm (5.2 lbf ft)

control Screw, water pump wheel M5 6 Nm (4.4 lbf ft) Remaining screws, engine M6 10 Nm (7.4 lbf ft) – Screw, clutch cover M6 10 Nm (7.4 lbf ft) – Screw, clutch spring M6 10 Nm (7.4 lbf ft) – Screw, control flap of exhaust control M6 10 Nm (7.4 lbf ft) Screw, engine housing M6 10 Nm (7.4 lbf ft) – Screw, gear oil level check M6 10 Nm (7.4 lbf ft) – Screw, intake flange M6 8 Nm (5.9 lbf ft) – Screw, intermediate wheel bolt M6 8 Nm (5.9 lbf ft) Screw, shift drum locating M6 10 Nm (7.4 lbf ft) Screw, shift lever M6 14 Nm (10.3 lbf ft) Screw, water pump cover M6 10 Nm (7.4 lbf ft) Remaining screws, engine M8 25 Nm (18.4 lbf ft) – Screw, cylinder head M8 27 Nm (19.9 lbf ft) – Screw, kickstarter M8 25 Nm (18.4 lbf ft) Nuts, cylinder base M10 35 Nm (25.8 lbf ft) – Remaining screws, engine M10 45 Nm (33.2 lbf ft) –

Loctite®222

Loctite®243™

Loctite®2701

Loctite®243™

TECHNICAL DATA - ENGINE TIGHTENING TORQUES 79

Drain plug, water pump cover M10x1 15 Nm (11.1 lbf ft) – Nut, rotor M12x1 60 Nm (44.3 lbf ft) – Gear oil drain plug with magnet M12x1.5 20 Nm (14.8 lbf ft) – Spark plug M14x1.25 25 Nm (18.4 lbf ft) – Nut, inner clutch hub M18x1.5 100 Nm (73.8 lbf ft) Nut, primary gear M18LHx1.5 150 Nm (110.6 lbf ft)

Loctite®2701

Loctite®243™

TECHNICAL DATA - CARBURETOR 80

15.1125 SX

Carburetor type KEIHIN PWK 38S AG Carburetor identification number AQ7 Needle position 3rd position from top Jet needle NOZI (NOZH, NOZJ) Main jet 182 (180, 185) Idling jet 42 (40, 45) Starting jet 85 Idle air adjusting screw

Open 1.5 turns Throttle slide 7 with cut-out

15.2Carburetor - basic setting for sandy surfaces (125 SX)

Idle air adjusting screw

Open 1.5 turns Idling jet 45 Jet needle NOZH Needle position 4th position from top Main jet 208

Info

If the engine is not running smoothly, use a smaller main jet.

TECHNICAL DATA - CARBURETOR 81

0044

33 0

15.3Carburetor configuration (125 SX)

M/FT ASL Sea level TEMP Temperature ASO Idle air adjusting screw is open IJ Idling jet NDL Needle POS Needle position from above MJ Main jet

1... 5 Needle position from above

The carburetor configuration depends on the defined ambient and operating conditions.

Info

Not for sandy surfaces

B00075-10

400709-01

TECHNICAL DATA - CARBURETOR 82

15.4150 SX

Carburetor type KEIHIN PWK 38S AG Carburetor identification number AQ8 Needle position 2nd position from top Jet needle NOZI (NOZH, NOZJ) Main jet 182 (180, 185) Idling jet 42 (40, 45) Starting jet 85 Idle air adjusting screw

Open 1.5 turns Throttle slide 6.5 with cut-out

15.5Carburetor - basic setting for sandy surfaces (150 SX)

Idle air adjusting screw

Open 1.5 turns Idling jet 45 Jet needle NOZH Needle position 3rd position from top Main jet 208

Info

If the engine is not running smoothly, use a smaller main jet.

TECHNICAL DATA - CARBURETOR 83

0044

33 0

15.6Carburetor configuration (150 SX)

M/FT ASL Sea level TEMP Temperature ASO Idle air adjusting screw is open IJ Idling jet NDL Needle POS Needle position from above MJ Main jet

1... 5 Needle position from above

The carburetor configuration depends on the defined ambient and operating conditions.

Info

Not for sandy surfaces

B00075-10

400710-01

TECHNICAL DATA - CARBURETOR 84

15.7250 SX

Carburetor type KEIHIN PWK 36S AG Carburetor identification number FK0180 Needle position 3rd position from top Jet needle N1EI (N1EH) Main jet 158 (155, 160) Idling jet 42 (40) Starting jet 85 Idle air adjusting screw

Open 1.0 turn Throttle slide 6,5

15.8Carburetor - basic setting for sandy surfaces (250 SX)

Idle air adjusting screw

Open 1.0 turn Idling jet 45 Jet needle NOZG Needle position 4th position from top Main jet 175

Info

If the engine is not running smoothly, use a smaller main jet.

TECHNICAL DATA - CARBURETOR 85

0044

33 0

15.9Carburetor configuration (250 SX)

M/FT ASL Sea level TEMP Temperature ASO Idle air adjusting screw is open IJ Idling jet NDL Needle POS Needle position from above MJ Main jet

1... 5 Needle position from above

The carburetor configuration depends on the defined ambient and operating conditions.

Info

Not for sandy surfaces

B00075-10

400711-01

TECHNICAL DATA - CHASSIS 86

Frame Central tube frame made of chrome molybdenum steel tubing Fork WP Suspension Up Side Down 4860 MXMA CC Suspension travel

Front 300 mm (11.81 in)

Rear 335 mm (13.19 in) Fork offset 22 mm (0.87 in) Shock absorber WP Suspension PDS 5018 DCC Brake system Disc brakes, brake calipers on floating bearings Brake discs - diameter

Front 260 mm (10.24 in)

Rear 220 mm (8.66 in) Brake discs - wear limit

Front 2.5 mm (0.098 in)

Rear 3.5 mm (0.138 in) Tire air pressure off road

Front 1.0 bar (15 psi)

Rear 1.0 bar (15 psi) Secondary ratio (125 SX) 13:50 Secondary ratio (150 SX) 14:50 Secondary ratio (250 SX) 13:48 Chain 5/8 x 1/4" Rear sprockets available 38, 40, 42, 45, 48, 49, 50, 51, 52 Steering head angle 63.5° Wheelbase (125 SX, 150 SX) 1,471±10 mm (57.91±0.39 in) Wheelbase (250 SX) 1,475±10 mm (58.07±0.39 in) Seat height unloaded 985 mm (38.78 in) Ground clearance unloaded (125 SX, 150 SX) 390 mm (15.35 in) Ground clearance unloaded (250 SX) 385 mm (15.16 in) Weight without fuel, approx. (125 SX, 150 SX) 90.8 kg (200.2 lb.) Weight without fuel, approx. (250 SX) 95.4 kg (210.3 lb.) Maximum permissible front axle load 145 kg (320 lb.) Maximum permissible rear axle load 190 kg (419 lb.) Maximum permissible overall weight 335 kg (739 lb.)

16.1Tires

Validity Front tire Rear tire

(125 SX, 150 SX) 80/100 - 21 51M TT

Bridgestone M59

(250 SX) 80/100 - 21 51M TT

Bridgestone M59

100/90 - 19 57M TT

Bridgestone M70

110/90 - 19 62M TT

Bridgestone M70

Additional information is available in the Service section under: http://www.ktm.com

16.2Capacity - fuel

Total fuel tank capacity, approx.

8 l (2.1 US gal) Super unleaded gasoline, mixed with 2-stroke engine oil (1:40)

( p. 95) (125 SX, 150 SX)

Super unleaded gasoline, mixed with 2-stroke engine oil (1:60)

( p. 95) (250 SX)

TECHNICAL DATA - FORK 87

17.1125 SX, 150 SX

Fork part number 14.18.7J.01 Fork WP Suspension Up Side Down 4860 MXMA CC Compression damping

Comfort 14 clicks

Standard 12 clicks

Sport 10 clicks Rebound damping

Comfort 14 clicks

Standard 12 clicks

Sport 10 clicks Spring length with preload spacer(s) 492 mm (19.37 in) Spring rate

Weight of rider: 65… 75 kg (143… 165 lb.) 4.0 N/mm (22.8 lb/in)

Weight of rider: 75… 85 kg (165… 187 lb.) 4.2 N/mm (24 lb/in)

Weight of rider: 85… 95 kg (187… 209 lb.) 4.4 N/mm (25.1 lb/in) Gas pressure 1.2 bar (17 psi) Fork length 940 mm (37.01 in)

Oil capacity per cartridge 195 ml (6.59 fl. oz.) Fork oil (SAE 5) ( p. 94) Oil capacity fork leg without

350 ml (11.83 fl. oz.) Fork oil (SAE 5) ( p. 94)

cartridge

17.2250 SX

Fork part number 14.18.7J.03 Fork WP Suspension Up Side Down 4860 MXMA CC Compression damping

Comfort 14 clicks

Standard 12 clicks

Sport 10 clicks Rebound damping

Comfort 14 clicks

Standard 12 clicks

Sport 10 clicks Spring length with preload spacer(s) 492 mm (19.37 in) Spring rate

Weight of rider: 65… 75 kg (143… 165 lb.) 4.2 N/mm (24 lb/in)

Weight of rider: 75… 85 kg (165… 187 lb.) 4.4 N/mm (25.1 lb/in)

Weight of rider: 85… 95 kg (187… 209 lb.) 4.6 N/mm (26.3 lb/in) Gas pressure 1.2 bar (17 psi) Fork length 940 mm (37.01 in)

Oil capacity per cartridge 195 ml (6.59 fl. oz.) Fork oil (SAE 5) ( p. 94) Oil capacity fork leg without

360 ml (12.17 fl. oz.) Fork oil (SAE 5) ( p. 94)

cartridge

TECHNICAL DATA - SHOCK ABSORBER 88

18.1125 SX, 150 SX

Shock absorber part number 12.18.7J.01 Shock absorber WP Suspension PDS 5018 DCC Compression damping, low-speed

Comfort 17 clicks

Standard 15 clicks

Sport 13 clicks Compression damping, high-speed

Comfort 2 turns

Standard 1.5 turns

Sport 1 turn Rebound damping

Comfort 24 clicks

Standard 22 clicks

Sport 22 clicks Spring preload 5 mm (0.2 in) Spring rate

Weight of rider: 65… 75 kg (143… 165 lb.) 60 N/mm (343 lb/in)

Weight of rider: 75… 85 kg (165… 187 lb.) 63 N/mm (360 lb/in)

Weight of rider: 85… 95 kg (187… 209 lb.) 66 N/mm (377 lb/in) Spring length 250 mm (9.84 in) Gas pressure 10 bar (145 psi) Static sag 33 mm (1.3 in) Riding sag 107 mm (4.21 in) Fitted length 411 mm (16.18 in) Shock absorber oil ( p. 95) SAE 2.5

18.2250 SX

Shock absorber part number 12.18.7J.03 Shock absorber WP Suspension PDS 5018 DCC Compression damping, low-speed

Comfort 17 clicks

Standard 15 clicks

Sport 13 clicks Compression damping, high-speed

Comfort 2 turns

Standard 1.5 turns

Sport 1 turn Rebound damping

Comfort 24 clicks

Standard 22 clicks

Sport 22 clicks Spring preload 6 mm (0.24 in) Spring rate

Weight of rider: 65… 75 kg (143… 165 lb.) 66 N/mm (377 lb/in)

Weight of rider: 75… 85 kg (165… 187 lb.) 69 N/mm (394 lb/in)

Weight of rider: 85… 95 kg (187… 209 lb.) 72 N/mm (411 lb/in) Spring length 250 mm (9.84 in) Gas pressure 10 bar (145 psi) Static sag 33 mm (1.3 in) Riding sag 105 mm (4.13 in) Fitted length 411 mm (16.18 in)

TECHNICAL DATA - SHOCK ABSORBER 89

Shock absorber oil ( p. 95) SAE 2.5

TECHNICAL DATA - TIGHTENING TORQUES FOR CHASSIS 90

Spoke nipple, front wheel M4.5 5… 6 Nm (3.7… 4.4 lbf ft) – Spoke nipple, rear wheel M5 5… 6 Nm (3.7… 4.4 lbf ft) – Remaining nuts, chassis M6 15 Nm (11.1 lbf ft) – Remaining screws, chassis M6 10 Nm (7.4 lbf ft) – Screw, ball joint of push rod on foot-

brake cylinder Screw, front brake disc M6 14 Nm (10.3 lbf ft) – Screw, rear brake disc M6 14 Nm (10.3 lbf ft) – Screw, shock absorber adjusting ring M6 5 Nm (3.7 lbf ft) – Nut, rear sprocket screw M8 35 Nm (25.8 lbf ft) Nut, rim lock M8 10 Nm (7.4 lbf ft) – Remaining nuts, chassis M8 30 Nm (22.1 lbf ft) – Remaining screws, chassis M8 25 Nm (18.4 lbf ft) – Screw, bottom triple clamp M8 12 Nm (8.9 lbf ft) – Screw, engine brace M8 33 Nm (24.3 lbf ft) – Screw, fork stub M8 15 Nm (11.1 lbf ft) – Screw, front brake caliper M8 25 Nm (18.4 lbf ft) Screw, handlebar clamp M8 20 Nm (14.8 lbf ft) – Screw, subframe M8 35 Nm (25.8 lbf ft) Screw, top triple clamp M8 17 Nm (12.5 lbf ft) – Engine bracket screw M10 60 Nm (44.3 lbf ft) – Remaining nuts, chassis M10 50 Nm (36.9 lbf ft) – Remaining screws, chassis M10 45 Nm (33.2 lbf ft) – Screw, handlebar support M10 40 Nm (29.5 lbf ft) Screw, bottom shock absorber M12 80 Nm (59 lbf ft) Screw, top shock absorber M12 80 Nm (59 lbf ft) Nut, seat fixing M12x1 20 Nm (14.8 lbf ft) – Nut, swingarm pivot M16x1.5 100 Nm (73.8 lbf ft) – Nut, rear wheel spindle M20x1.5 80 Nm (59 lbf ft) – Screw, top steering head M20x1.5 10 Nm (7.4 lbf ft) – Screw-in nozzles, cooling system M20x1.5 12 Nm (8.9 lbf ft) Screw, front wheel spindle M24x1.5 45 Nm (33.2 lbf ft) –

M6 10 Nm (7.4 lbf ft) –

Loctite®243™

WIRING DIAGRAM 92

re-wh re-bl

bu-wh

ye-bl

gn re

gr-bl

20.1Wiring diagram

B00059-10

WIRING DIAGRAM 93

Components

A6 CDI controller G2 Generator L1 Pulse generator L2 Ignition coil X1 Plug-in connector, ignition curve S9 Short circuit button

Cable colors

gn Green gr-bl Gray-black gr Gray bl Black ye-bl Yellow-black bu-wh Blue-white re Red re-wh Red-white re-bl Red-black br Brown

SUBSTANCES 94

Brake fluid DOT 4 / DOT 5.1

according to

– DOT

Guideline

– Use only brake fluid that complies with the specified standards (see specifications on the container) and that possesses the corre-

sponding properties. KTM recommends Castrol and Motorex®products.

Supplier Castrol – RESPONSE BRAKE FLUID SUPER DOT 4

Motorex – Brake Fluid DOT 5.1

Coolant

Guideline

– Use only suitable coolant (also in countries with high temperatures). Use of low-quality antifreeze can lead to corrosion and foam-

ing. KTM recommends Motorex®products.

Mixture ratio

Antifreeze protection: −25… −45 °C (−13…

−49 °F)

50 % corrosion inhibitor/antifreeze 50 % distilled water

Coolant (mixed ready to use)

Antifreeze −40 °C (−40 °F)

Supplier

Motorex – Anti Freeze

Engine oil (15W/50)

according to

– JASO T903 MA ( p. 98) – SAE ( p. 98) (15W/50)

Guideline

– Use only engine oils that comply with the specified standards (see specifications on the container) and that possess the corre-

sponding properties. KTM recommends Motorex®products.

Supplier

Motorex – Top Speed 4T

Fork oil (SAE 5)

according to

– SAE ( p. 98) (SAE 5)

Guideline

– Use only oils that comply with the specified standards (see specifications on the container) and that possess the corresponding

properties. KTM recommends Motorex®products.

Supplier

Motorex – Racing Fork Oil

Hydraulic fluid (15)

according to

– ISO VG (15)

Guideline

– Use only hydraulic fluid that complies with the specified standards (see specifications on the container) and that possesses the

corresponding properties. KTM recommends Motorex®products.

Supplier

Motorex – Hydraulic Fluid 75

SUBSTANCES 95

Shock absorber oil (SAE 2.5) (50180342S1)

according to

– SAE ( p. 98) (SAE 2.5)

Guideline

– Use only oils that comply with the specified standards (see specifications on the container) and that possess the corresponding

properties.

Super unleaded gasoline, mixed with 2-stroke engine oil (1:40)

according to

– DIN EN 228 – JASO FC ( p. 98) (1:40)

Mixture ratio

1:40 2-stroke engine oil

Super unleaded (ROZ 95 / RON 95 / PON 91)

Super unleaded gasoline, mixed with 2-stroke engine oil (1:60)

according to

– DIN EN 228 – JASO FC ( p. 98) (1:60)

Mixture ratio

1:60 2-stroke engine oil

Super unleaded (ROZ 95 / RON 95 / PON 91)

AUXILIARY SUBSTANCES 96

Air filter cleaner

Guideline

–

KTM recommends Motorex®products.

Supplier

Motorex – Twin Air Dirt Bio Remover

Chain cleaner

Guideline

–

KTM recommends Motorex®products.

Supplier

Motorex – Chain Clean 611

Cleaning and polishing materials for metal, rubber and plastic

Guideline

–

KTM recommends Motorex®products.

Supplier

Motorex – Protect & Shine 645

Contact spray

Guideline

–

KTM recommends Motorex®products.

Supplier

Motorex – Accu Contact

Long-life grease

Guideline

–

KTM recommends Motorex®products.

Supplier

Motorex – Fett 2000

Motorcycle cleaner

Guideline

–

KTM recommends Motorex®products.

Supplier

Motorex – Moto Clean 900

Off-road chain spray

Guideline

–

KTM recommends Motorex®products.

Supplier

Motorex – Chain Lube 622

Oil for foam air filter

Guideline

–

KTM recommends Motorex®products.

Supplier

Motorex – Twin Air Liquid Bio Power

AUXILIARY SUBSTANCES 97

Universal oil spray

Guideline

–

KTM recommends Motorex®products.

Supplier

Motorex – Joker 440 Universal

STANDARDS 98

JASO T903 MA

Different technical development directions required a new specification for 4-stroke motorcycles – the JASO T903 MA Standard. Earlier, engine oils from the automobile industry were used for 4-stroke motorcycles because there was no separate motorcycle specification. Whereas long service intervals are demanded for automobile engines, high performance at high engine speeds are in the foreground for motorcycle engines. With most motorcycles, the gearbox and the clutch are lubricated with the same oil as the engine. The JASO MA Standard meets these special requirements.

SAE

The SAE viscosity classes were defined by the Society of Automotive Engineers and are used for classifying oils according to their viscosity. The viscosity describes only one property of oil and says nothing about quality.

JASO FC

JASO FC is a classification for a 2-stroke engine oil that was specifically developed for the extreme demands of racing. Thanks to first rate synthetic esters and specially designed additives, superb combustion is achieved even under extreme operating conditions.

KTM 250 SX, 150 SX User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

MEANS OF REPRESENTATION 4

IMPORTANT INFORMATION 5

VIEW OF VEHICLE 7

3.1View of the vehicle from the left front (example)

3.2View of the vehicle from the right rear (example)

LOCATION OF SERIAL NUMBERS 9

4.1Chassis number

4.2Type label

4.3Engine number

4.4Fork part number

4.5Shock absorber part number

CONTROLS 10

5.1Clutch lever

5.2Hand brake lever

5.3Short circuit button

5.4Throttle grip

5.5Fuel tap

5.6Opening the filler cap

5.7Closing the filler cap

5.8Choke

5.9Shift lever

5.10Kickstarter

5.11Foot brake lever

5.12Plug-in stand

GENERAL TIPS AND HINTS ON PUTTING INTO OPERATION 14

6.1Advice on first use

6.2Running in the engine

6.3Preparing the vehicle for difficult operating conditions

6.4Preparations for riding on dry sand

6.5Preparations for riding on wet sand

6.6Preparations for riding on wet and muddy surfaces

6.7Preparations for riding at high temperatures and riding slowly

6.8Preparations for riding at low temperatures and in snow

RIDING INSTRUCTIONS 19

7.1Checks before putting into operation

7.2Starting

7.3Starting up

7.4Shifting, riding

7.5Braking

7.6Stopping, parking

7.7Refueling

SERVICE SCHEDULE 23

8.1Important maintenance work that must be done in an authorized KTM workshop

8.2Important maintenance work to be carried out by an authorized KTM workshop (as additional order)

8.3Important checks and maintenance work to be carried out by the rider

MAINTENANCE WORK ON CHASSIS AND ENGINE 26

9.1Jacking up the motorcycle

9.2Removing the motorcycle from the work stand

9.3Checking the basic chassis setting with the rider's weight

9.4Compression damping of shock absorber

9.5Adjusting the high-speed compression damping of the shock absorber

9.6Adjusting the low-speed compression damping of the shock absorber

9.7Adjusting the rebound damping of the shock absorber

9.8Measuring the sag of the unloaded rear wheel

9.9Checking the static sag of the shock absorber

9.10Checking the riding sag of the shock absorber

9.15Checking the basic setting of the fork

9.16Adjusting the compression damping of the fork

9.17Adjusting the rebound damping of the fork

9.18Bleeding the fork legs

9.19Cleaning the dust boots of the fork legs

9.20Loosening the fork protection

9.21Positioning the fork protection

9.22Checking the play of the steering head bearing

9.31Removing the front fender

9.32Installing the front fender

9.33Removing the start number plate

9.34Installing the start number plate

9.35Handlebar position

9.37Checking the play in the throttle cable

9.39Checking the chain for dirt

9.40Cleaning the chain

9.41Checking the chain tension

9.42Checking the rear sprocket/engine sprocket for wear

9.43Checking chain wear

9.44Adjusting the chain tension