. OWNER'S MANUAL 2015 125 SX EU 125 SX US 150 SX EU 150 SX US 250 SX EU 250 SX US 250 XC EU/US 300 XC EU/US Art. KTM accepts no liability for delivery options, deviations from illustrations and descriptions, as well as misprints and other errors. TABLE OF CONTENTS Starting.23 TABLE OF CONTENTS MEANS OF REPRESENTATION.5 Starting off. 24 Symbols used. 5 Shifting, riding.24 Formats used.

1. 2014 Ktm 125 Sx Service Manual
2. 2015 Ktm 125 Sx Service Manual

5 Braking.24 SAFETY ADVICE.6 Stopping, parking.25 Use definition - intended use.6 Transport. TABLE OF CONTENTS 15.5 Checking the antifreeze and coolant level.80 11.24 Removing the air filter. 49 15.6 Checking the coolant level.

81 11.25 Cleaning the air filter and air filter box.49 15.7 Draining the coolant. TABLE OF CONTENTS 21.4 Capacities. 112 21.4.1 Gear oil.

112 21.4.2 Coolant. 112 21.4.3 Fuel.112 21.5 Chassis.112 21.6 Electrical system. 113 21.7 Tires.113 21.8 Fork.

113 21.8.1 125 SX EU, 150 SX EU.113 21.8.2 125 SX US, 150 SX US. All work marked with this symbol requires specialist knowledge and technical understanding. In the interest of your own safety, have these jobs performed by an authorized KTM workshop. There, your motorcycle will be opti- mally cared for by specially trained experts using the specialist tools required. Use definition - intended use (All SX models) 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. Keep the Owner's Manual in an accessible place to enable you to refer to it as needed. If you would like to know more about the vehicle or have questions on the material you read, please contact an authorized KTM dealer. Guarantee, warranty The work prescribed in the service schedule must be carried out by an authorized KTM workshop only and confirmed in the customer's Service & Warranty Booklet and in the KTM dealer.net; otherwise, all warranty claims will be void.

No warranty claims can be consid- ered for damage resulting from manipulations and/or alterations to the vehicle. VIEW OF VEHICLE View of the vehicle from the left front (example) B02068-10 Hand brake lever ( p. 12) Kill switch ( p. 12) Clutch lever ( p. 12) Air filter box lid Fuel tap Choke ( p.

15) Shift lever ( p. VIEW OF VEHICLE View of vehicle, rear right (example) B02069-10 Seat Filler cap Throttle grip ( p. 12) Shock absorber rebound adjustment Level viewer for brake fluid, rear Shock absorber compression adjustment Foot brake lever ( p.

16) Kick starter ( p. SERIAL NUMBERS Chassis number  The chassis number is stamped on the right side of the steering head. 401945-10 Type label The type label  is fixed to the front of the steering head. 401946-10 Engine number  The engine number is stamped on the left side of the engine under the engine sprocket. CONTROLS Clutch lever (125/150 SX)  The clutch lever is fitted on the left side of the handlebar.

The clutch is hydraulically operated and self-adjusting. 101655-10 (All 250/300 models)  The clutch lever is fitted on the left side of the handlebar.

The clutch is hydraulically operated and self-adjusting. CONTROLS Electric starter button (All XC models)  The electric starter button is fitted on the right side of the handlebar. Possible states. Electric starter button in basic position pressed – In this position, the electric starter is actuated. CONTROLS Closing the filler cap (All SX models) –  Mount filler cap and turn it clockwise until the fuel tank is tightly closed. Info  Run the fuel tank breather hose without kinks.

B02071-11 (All XC models) –  Mount filler cap and turn it clockwise until the release button engages. CONTROLS Fuel tap (All XC models) The fuel tap is on the left side of the fuel tank.

 Tap handle on the fuel tap is used to open or close the supply of fuel to the carbu- retor. Possible states Fuel supply closed OFF –. CONTROLS (250 SX EU, 250 SX US) The gear positions can be seen in the photograph.

The neutral or idle position is between the first and second gears. 401950-13 6.12 Kick starter The kick starter  is fitted on the right side of the engine. The top part can be swiveled. CONTROLS The side stand is used to park the motorcycle.

Info  When you are riding, side stand must be folded up and secured with rubber  band 401944-10. 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. PREPARING FOR USE – Do not exceed the overall maximum permitted weight and the axle loads. 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.) –. Info Read the KTM PowerParts installation instructions.

– Adjust the carburetor jetting and setting. Info B00436-01 Your authorized KTM workshop can recommend the right carburetor tuning. – Clean the chain. Chain cleaner ( p.

121) – Mount the steel sprocket. Rain cover for air filter (0) Info Follow the KTM PowerParts mounting instructions. – Adjust the carburetor jetting and setting. Info B00437-01 Your authorized KTM workshop can recommend the right carburetor tuning. – Mount the steel sprocket. – Clean the motorcycle.

Mount the rain cover for the air filter. Rain cover for air filter (0) Info Follow the KTM PowerParts mounting instructions. – Adjust the carburetor jetting and setting. Info B00437-01 Your authorized KTM workshop can recommend the right carburetor tuning. RIDING INSTRUCTIONS Checks and maintenance work when preparing for use Info Before riding the vehicle, always check its condition and operating safety. The vehicle must be in perfect technical condition when used.

– Check the gear oil level. Do not change into a low gear at high engine speed. The engine races and the rear wheel can lock up. 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.

RIDING INSTRUCTIONS – 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. – Make use of the braking effect of the engine when driving down long downhill stretches. To do so, shift back one or two gears, but do not overrev the engine.

RIDING INSTRUCTIONS Refueling 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. Check the screws and nuts for tightness.

● ● Check the idle. ● ● Final check: Check the vehicle for safe operation and take a test ride.

● ● Make the service entry in KTM DEALER.NET and in the service record. ● Periodic interval.

SERVICE SCHEDULE 9.1.2 Service work (as additional order) Annually Every 40 operating hours - corresponds to about 280 liters of fuel (74 US gal) Every 30 operating hours - corresponds to about 210 liters of fuel (55.5 US gal) Once after 20 operating hours Every 10 operating hours - corresponds to about 70 liters of fuel (18.5 US gal) / after every race Once after 10 operating hours ●. Check the idle. ● ● Final check: Check the vehicle for safe operation and take a test ride. ● ● Make the service entry in KTM DEALER.NET and in the service record. ● Periodic interval 9.2.2 Service work (as additional order) Annually.

Caution 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. Caution 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. Adjusting the rebound damping of the shock absorber Caution 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.) – . TUNING THE CHASSIS 10.6 Measuring the sag of the unloaded rear wheel Preparatory work – Raise the motorcycle with the lift stand. 39) Main work – Measure the distance – as vertically as possible – between the rear axle and a fixed point such as a mark on the side cover.

Caution 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.

TUNING THE CHASSIS Main work – Choose and mount a suitable spring. Guideline Spring rate (125/150 SX) Weight of rider: 65 75 kg (143 45 N/mm (257 lb/in) 165 lb.) Weight of rider: 75 85 kg (165 48 N/mm (274 lb/in) 187 lb.) Weight of rider: 85. TUNING THE CHASSIS 10.12 Adjusting the compression damping of the fork Info The hydraulic compression damping determines the fork suspension behavior. (125 SX EU, 150 SX EU, 250 SX EU) –  Turn adjusting screws clockwise all the way. TUNING THE CHASSIS 10.13 Adjusting the rebound damping of the fork Info The hydraulic rebound damping determines the fork suspension behavior.

(125 SX EU, 150 SX EU, 250 SX EU) –  Remove protection caps –  Turn adjusting screws clockwise all the way. TUNING THE CHASSIS 10.14 Handlebar 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. SERVICE WORK ON THE CHASSIS 11.1 Raising the motorcycle with the lift stand Note Danger of damage The parked vehicle may roll away or fall over.

– Always place the vehicle on a firm and even surface. – Raise the motorcycle at the frame underneath the engine. Lift stand (0) The wheels must no longer touch the ground. SERVICE WORK ON THE CHASSIS 11.4 Cleaning the dust boots of the fork legs Preparatory work – Raise the motorcycle with the lift stand. 39) – Remove the fork protector. 41) Main work –  Push dust boots of both fork legs downwards. SERVICE WORK ON THE CHASSIS 11.6 Installing the fork legs Main work – Position the fork legs.

Bleeder screws  face forward. Info Grooves are milled into the side of the upper end of the fork legs. The sec- ond milled groove (from the top) must be flush with the top edge of the upper triple clamp. SERVICE WORK ON THE CHASSIS 11.9 Removing the lower triple clamp Preparatory work – Raise the motorcycle with the lift stand. 39) – Remove the front wheel.

71) – Remove the fork legs. 40) – Remove the start number plate. SERVICE WORK ON THE CHASSIS (125 SX EU, 150 SX EU, 250 SX EU) – Position the fork legs. Bleeder screws  face toward the front. Info Grooves are milled into the side of the upper end of the fork legs. The second milled groove (from the top) must be flush with the top edge of the upper triple clamp.

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 with play in the steering head bearing, the bearing and the bearing seats in the frame can become dam- aged over time.

SERVICE WORK ON THE CHASSIS 11.12 Adjusting the play of the steering head bearing Preparatory work – Raise the motorcycle with the lift stand. 39) – Remove the handlebar cushion. Main work –   Loosen screws. Remove screw –. SERVICE WORK ON THE CHASSIS 11.15 Installing the start number plate –  Position the start number plate.

Mount and tighten screw Guideline Remaining screws, chassis 10 Nm (7.4 lbf ft) Info Ensure that the holding lugs engage in the fender. SERVICE WORK ON THE CHASSIS 11.18 Removing the shock absorber Preparatory work – Raise the motorcycle with the lift stand. 39) – Remove the main silencer. 51) Main work –  Remove screw –  Remove screw cap B02098-10 –. SERVICE WORK ON THE CHASSIS 11.20 Removing the seat –  Remove screw.

Lift up the seat at the rear, pull it back and then remove from above. 101683-10 11.21 Mounting 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.

SERVICE WORK ON THE CHASSIS 11.23 Installing the air filter box lid –   Insert the air filter box lid into rear area and clip it into front area B02101-12 Condition The air filter box lid is secured. SERVICE WORK ON THE CHASSIS Main work – Wash the air filter thoroughly in special cleaning liquid and allow it to dry properly. Air filter cleaner ( p.

121) Info Only squeeze the air filter to dry it; never wring it out. SERVICE WORK ON THE CHASSIS 11.28 Sealing the air filter box Preparatory work – Remove the air filter box lid. 48) Main work –  Seal the air filter box in the marked area 401527-10 Finishing work – Install the air filter box lid. SERVICE WORK ON THE CHASSIS Main work –   Remove screws.

2014 Ktm 125 Sx Service Manual

Pull out inner tube –  Pull the glass fiber yarn filling from the inner tube. – Clean the parts that are to be reinstalled. –  Mount the new glass fiber yarn filling on the inner tube. SERVICE WORK ON THE CHASSIS –  Remove screw with the rubber bushing. – Remove the tube from the fuel tank vent line.

L00951-11 – Pull both spoilers off of the sides of the radiator bracket and lift off the fuel tank. 101689-01 11.33 Installing the fuel tank. SERVICE WORK ON THE CHASSIS –  Mount and tighten screws with the collar bushings. Guideline Remaining screws, chassis 10 Nm (7.4 lbf ft) – Connect the fuel hose. 101687-11 Finishing work – Mount the seat. 48) 11.34 Checking the chain for dirt –.

SERVICE WORK ON THE CHASSIS 11.36 Checking the chain tension Warning Danger of accidents Danger caused by incorrect chain tension. – If the chain is too taut, the components of the secondary power transmission (chain, engine sprocket, rear sprocket, bear- ings in the transmission and in the rear wheel) will be under additional load. In addition to premature wear, this can cause the chain or the countershaft of the transmission to break in extreme cases. SERVICE WORK ON THE CHASSIS Info The wide adjustment range of the chain adjusters (32 mm) enables different secondary ratios with the same chain length.

Chain adjusters  can be turned by 180°. Finishing work – Remove the motorcycle from the lift stand. If the frame exhibits cracking or deformation due to a mechanical impact: – Change the frame. Info A frame that has been damaged due to a mechanical impact must always be changed.

Repair of the frame is not authorized by KTM. If the swingarm shows signs of damage, cracking, or deformation: – Change the swingarm. Info A damaged swingarm must always be changed. Repair of the swingarm is not authorized by KTM. 500285-01 11.41 Checking the routing of the throttle cable Preparatory work –. SERVICE WORK ON THE CHASSIS (All XC models) – Check the routing of the throttle cable.

The throttle cable must be routed along the back of the handlebar, to the right of the frame, below the fuel tank bracket, and to the carburetor. SERVICE WORK ON THE CHASSIS Info When the adjusting screw is turned counterclockwise, the clutch lever moves away from the handlebar. When the adjusting screw is turned clockwise, the clutch lever moves closer to the handlebar. The range of adjustment is limited. Turn the adjusting screw by hand only, and do not apply any force. SERVICE WORK ON THE CHASSIS 11.46 Changing the hydraulic clutch fluid 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. (125/150 SX) – Move the clutch fluid reservoir mounted on the handlebar to a horizontal posi- tion. SERVICE WORK ON THE CHASSIS –  Inject the liquid into the system until it escapes from bore hole of the mas- ter cylinder without bubbles. – To prevent overflow, drain fluid occasionally from the master cylinder reservoir. – Remove the bleeding syringe. Mount and tighten the bleeder screw.

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 . KTM workshop will be glad to help.) Warning Danger of accidents Reduced braking efficiency due to old brake fluid. – Change the brake fluid of the front and rear brake according to the service schedule.

(Your authorized KTM workshop will be glad to help.) Preparatory work –. Warning Danger of accidents Reduced braking efficiency due to old brake fluid. – Change the brake fluid of the front and rear brake according to the service schedule. (Your authorized KTM workshop will be glad to help.) Warning Danger of accidents Reduced braking efficiency due to oil or grease on the brake discs. 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 origi- nal license.

BRAKE SYSTEM –  Correct the brake fluid quantity to level Guideline 5 mm (0.2 in)  Dimension (brake fluid level below top edge of container) Brake fluid DOT 4 / DOT 5.1 ( p. 119) – Position the cover with the membrane. Mount and tighten the screws. Info L00956-11 Wash off overflowed or spilled brake fluid immediately with water. KTM workshop will be glad to help.) Warning Danger of accidents Reduced braking efficiency due to old brake fluid.

– Change the brake fluid of the front and rear brake according to the service schedule. (Your authorized KTM workshop will be glad to help.) Preparatory work –. Warning Danger of accidents Reduced braking efficiency due to old brake fluid.

– Change the brake fluid of the front and rear brake according to the service schedule. (Your authorized KTM workshop will be glad to help.) Warning Environmental hazard Hazardous substances cause environmental damage.

BRAKE SYSTEM – Stand the vehicle upright. –   Remove screw cap with membrane and the O-ring. 101705-10 – Manually press the brake caliper to the brake disc to push back the brake piston. Ensure that brake fluid does not flow out of the brake fluid reservoir, extracting it by suction if it does. WHEELS, TIRES 13.1 Removing the front wheel Preparatory work – Raise the motorcycle with the lift stand.

39) Main work – Press the brake caliper onto the brake disc by hand in order to push back the brake pistons. WHEELS, TIRES – Lift the front wheel into the fork, position it, and insert the wheel spindle. The brake linings are correctly positioned. – Mount and tighten screw  Guideline Screw, front wheel spindle M20x1.5 35 Nm (25.8 lbf ft) –.

Checking 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. 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.) Info A loose spoke causes wheel imbalance and rapidly leads to more loose spokes. WHEELS, TIRES » If the spoke tension varies: – Correct the spoke tension. – Check the spoke torque. Guideline Spoke nipple, front wheel M4.5 6 Nm (4.4 lbf ft) Spoke nipple, rear wheel M4.5 6 Nm (4.4 lbf ft) Torque wrench with various accessories in set (0). ELECTRICAL SYSTEM 14.1 Removing the battery (All XC models) Warning Risk of injury Battery acid and battery gases cause serious chemical burns.

– Keep batteries out of the reach of children. – Wear suitable protective clothing and goggles. – Avoid contact with battery acid and battery gases. – Do not discard batteries with the household waste. Dispose of faulty batteries in an environmentally compatible manner.

Give the battery to your authorized KTM dealer or dispose of it at a collection point for used batteries. Warning Environmental hazard Hazardous substances cause environmental damage.

ELECTRICAL SYSTEM 14.4 Changing the main fuse (All XC models) Warning Fire hazard The electrical system can be overloaded if the wrong fuses are used. – Use only fuses with the prescribed amperage. Never by-pass or repair fuses. Info The main fuse protects all power consumers of the vehicle. It is located in the starter relay housing under the air filter box cover.

COOLING SYSTEM 15.1 Cooling system (125/150 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. COOLING SYSTEM –  Position the corresponding radiator cover and attach the radiator shield at hold- ing lugs . Attach mounting points  at the radiator. L00930-10 15.4 Removing the radiator cover (All SX models) – Detach radiator shield . COOLING SYSTEM » If the level of the coolant does not meet specifications: – Correct the coolant level.

Alternative 1 Coolant ( p. 119) Alternative 2 Coolant (mixed ready to use) ( p. 119) – Mount the radiator cap. 15.6 Checking the coolant level Warning Danger of scalding During motorcycle operation, the coolant gets very hot and is under pressure. COOLING SYSTEM (125/150 SX) –   Remove screw. Take off radiator cap – Completely drain the coolant.

2015 Ktm 125 Sx Service Manual

–  Mount and tighten screw with a new seal ring. Guideline Drain plug, water pump cover M10x1 15 Nm (11.1 lbf ft) B02123-11 (All 250/300 models) –. TUNING THE ENGINE 16.1 Checking the play in the throttle cable – Check the throttle grip for smooth operation. – Move the handlebar to the straight-ahead position. Move the throttle grip back and  forth slightly to determine the play in throttle cable Play in throttle cable 2. TUNING THE ENGINE 16.3 Carburetor - idle The idle setting of the carburetor has a big influence on the starting behavior, stable idling and the response to throttle opening. This means that 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. TUNING THE ENGINE Guideline Idle air adjusting screw (125 SX EU, 125 SX US) Open 2 turns Idle air adjusting screw (150 SX EU, 150 SX US) Open 2 turns Idle air adjusting screw (250 SX EU, 250 SX US) Open 2 turns Idle air adjusting screw (250 XC EU/US).

TUNING THE ENGINE 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. TUNING THE ENGINE 16.9 Adjusting the basic position of the shift lever –   Remove screw and take off shift lever 401950-12 –  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. TUNING THE ENGINE –     Take cap, adjusting spring, auxiliary spring, and spring insert out of the clutch cover.

– Pull both springs off of the spring insert. B00056-11 –   Mount the required auxiliary spring and adjusting spring and slide them into the clutch cover together. SERVICE WORK ON THE ENGINE 17.1 Checking the gear oil level Info The gear oil level must be checked while the engine is cold.

Preparatory work – Stand the motorcycle upright on a horizontal surface. Main work (125/150 SX) – . SERVICE WORK ON THE ENGINE 17.3 Draining the gear oil 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.

SERVICE WORK ON THE ENGINE Main work –  Remove screw cap and fill up gear oil. 0 0 1 Gear oil (125/150 0.70 l (0.74 qt.) Engine oil (15W/50) ( p.

119) Gear oil (All 0.80 l (0.85 qt.) Engine oil (15W/50) ( p. SERVICE WORK ON THE ENGINE –  Mount and tighten screw cap Finishing work Danger Danger of poisoning Exhaust gases are toxic 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. CLEANING, CARE 18.1 Cleaning the motorcycle Note Material damage Damage and destruction of components by high-pressure cleaning equipment. – When cleaning the vehicle with a pressure cleaner, do not point the water jet directly onto electrical components, connectors, cables, bearings, etc. Maintain a minimum distance of 60 cm between the nozzle of the pressure cleaner and the component.

Excessive pressure can cause malfunctions or destroy these parts. – Store the vehicle in a dry location that is not subject to large fluctuations in tem- perature. Info KTM recommends lifting the motorcycle.

– Raise the motorcycle with the lift stand. 39) – Cover the vehicle with a tarp or cover that is permeable to air. TROUBLESHOOTING Faults Possible cause Action – The engine cannot be cranked (elec- Operating error Go through the steps of starting the engine. Tric starter) p.

23) (All XC models) – Battery discharged Recharge the battery. 77) – Check the charging voltage. TROUBLESHOOTING Faults Possible cause Action (All SX models) Engine stalls or is popping into the Lack of fuel – carburetor  Turn handle of the fuel tap to the ON position. (Figure B02072-10 p. 14) (All XC models) –  Turn handle of the fuel tap to the ON position.

TECHNICAL DATA 21.1 Engine 21.1.1 125 SX EU, 125 SX US 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. TECHNICAL DATA 5th gear 19:23 6th gear 22:24 Ignition Contactless controlled fully electronic ignition with digital igni- tion adjustment, type Kokusan 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 Kick starter 21.1.3. TECHNICAL DATA Conrod bearing Needle bearing Piston pin bearing Needle bearing Pistons Aluminum cast Piston rings 2 half keystone rings X (upper edge of piston to upper edge of cylinder) 0 0.10 mm (0 0.0039 in) Z (height of control flap) 48 mm (1.89 in) Primary transmission 26:72.

TECHNICAL DATA Spark plug NGK BR 7 ES Spark plug electrode gap 0.60 mm (0.0236 in) Starting aid Kick starter and electric starter 21.2 Engine tightening torques 21.2.1 125/150 SX – Screw, inner reed valves EJOT DELTA PT ® 35x25 1 Nm (0.7 lbf ft) –. TECHNICAL DATA 21.2.2 250 SX EU, 250 SX US – Screw, inner reed petals EJOT DELTA PT ® 35x25 1 Nm (0.7 lbf ft) – Screw, membrane core plate EJOT DELTA PT ® 30x12 1 Nm (0.7 lbf ft) – EJOT DELTA PT ®.

TECHNICAL DATA Loctite ® 243™ Screw, retaining bracket of exhaust 7 Nm (5.2 lbf ft) control Screw, water pump wheel 6 Nm (4.4 lbf ft) Loctite ® 243™ – Screw, alternator cover 8 Nm (5.9 lbf ft) Screw, bearing retainer 10 Nm (7.4 lbf ft) Loctite ®. TECHNICAL DATA 21.3 Carburetor 21.3.1 125 SX EU, 125 SX US Carburetor type KEIHIN PWK 38S AG Carburetor identification number BS50 Needle position 4th position from top Jet needle NOZH (NOZG, NOZI) Main jet 182 (180, 185) Idling jet 42 (40, 45) Starting jet Idle air adjusting screw Open. TECHNICAL DATA 21.3.3 Carburetor tuning (125 SX EU, 125 SX US) 401762-01 M/FT ASL Sea level TEMP Temperature Idle air adjusting screw open Idling jet Needle Needle position from above Main jet Info Not for sandy surfaces. TECHNICAL DATA 21.3.4 150 SX EU, 150 SX US Carburetor type KEIHIN PWK 38S AG Carburetor identification number BS60 Needle position 3rd position from top Jet needle N1EJ (N1EI, N1EK) Main jet 180 (178, 182) Idling jet 40 (42) Starting jet Idle air adjusting screw Open 2 turns. TECHNICAL DATA 21.3.6 Carburetor tuning (150 SX EU, 150 SX US) 401763-01 M/FT ASL Sea level TEMP Temperature Idle air adjusting screw open Idling jet Needle Needle position from above Main jet Info Not for sandy surfaces. TECHNICAL DATA 21.3.7 250 SX EU, 250 SX US Carburetor type KEIHIN PWK 36S AG Carburetor identification number BS80 Needle position 4th position from top Jet needle N1EH (N1EG, N1EI) Main jet 158 (155, 160) Idling jet 42 (40) Starting jet Idle air adjusting screw Open 2 turns. TECHNICAL DATA 21.3.9 Carburetor tuning (250 SX EU, 250 SX US) 401764-01 M/FT ASL Sea level TEMP Temperature Open idle air adjusting screw Idling jet Needle Needle position from above Main jet Info Not for sandy surfaces.

TECHNICAL DATA 21.3.10 250 XC EU/US Carburetor type KEIHIN PWK 36S AG Carburetor identification number BZ6A Needle position 3rd position from top Jet needle N2ZW (N2ZH, N2ZJ) Main jet 175 (172) Idling jet 38 (40) Starting jet Idle air adjusting screw Open 2 turns Throttle slide. TECHNICAL DATA Needle Needle position from above Main jet Info Not for sandy surfaces. TECHNICAL DATA 21.3.12 300 XC EU/US Carburetor type KEIHIN PWK 36S AG Carburetor identification number BZ7A Needle position 3rd position from top Jet needle N8RG (N8RH) Main jet 172 (170, 175) Idling jet Starting jet Idle air adjusting screw Open 2 turns Throttle slide 7 with cut-out.

TECHNICAL DATA Needle Needle position from above Main jet Info Not for sandy surfaces 21.4 Capacities 21.4.1 Gear oil Gear oil (125/150 SX) 0.70 l (0.74 qt.) Engine oil (15W/50) ( p. 119) Gear oil (All 250/300 models) 0.80 l (0.85 qt.) Engine oil (15W/50) ( p. 90/90 - 21 54M TT 110/100 - 18 64M TT Dunlop GEOMAX AT 81 F Dunlop GEOMAX AT 81 Additional information is available in the Service section under: 21.8 Fork 21.8.1 125 SX EU, 150 SX EU Fork part number 14.18.7O.01. TECHNICAL DATA Oil capacity fork leg without 370 ml (12.51 fl. Oz.) Fork oil (SAE 4) (48601166S1) ( p. 119) cartridge 21.8.2 125 SX US, 150 SX US Fork part number 24.18.7O.51 Fork WP Suspension Up Side Down 4860 MXMA 4CS Compression damping Comfort 17 clicks.

TECHNICAL DATA Rebound damping Comfort 17 clicks Standard 15 clicks Sport 13 clicks Spring length with preload spacer(s) 480 mm (18.9 in) Spring rate Weight of rider: 65 75 kg (143 165 lb.) 4.4 N/mm (25.1 lb/in) Weight of rider: 75 85 kg (165 187 lb.) 4.6 N/mm (26.3 lb/in) Weight of rider: 85. TECHNICAL DATA Weight of rider: 75 85 kg (165 187 lb.) 48 N/mm (274 lb/in) Weight of rider: 85 95 kg (187 209 lb.) 51 N/mm (291 lb/in) Spring length 260 mm (10.24 in) Gas pressure 10 bar (145 psi) Static sag 30 mm (1.18 in) Riding sag. TECHNICAL DATA Spring rate Weight of rider: 65 75 kg (143 165 lb.) 51 N/mm (291 lb/in) Weight of rider: 75 85 kg (165 187 lb.) 54 N/mm (308 lb/in) Weight of rider: 85 95 kg (187 209 lb.) 57 N/mm (325 lb/in) Spring length 260 mm (10.24 in) Gas pressure.

TECHNICAL DATA Loctite ® 243™ Screw, front brake disc 14 Nm (10.3 lbf ft) Screw, rear brake disc 14 Nm (10.3 lbf ft) Loctite ® 243™ – Screw, throttle grip 5 Nm (3.7 lbf ft) – Nut, foot brake lever stop 20 Nm (14.8 lbf ft) Nut, rear sprocket screw 35 Nm (25.8 lbf ft). SUBSTANCES 2-stroke engine oil Standard/classification – JASO FC ( p. 123) Guideline – Only use high grade 2-stroke engine oil of a reputable brand. Fully synthetic Recommended supplier Motorex ® – Cross Power 2T Brake fluid DOT 4 / DOT 5.1 Standard/classification –. SUBSTANCES Hydraulic fluid (15) Standard/classification – ISO VG (15) Guideline – Use only hydraulic oil that complies with the specified standard (see specifications on the container) and that possesses the corre- sponding properties. Recommended supplier Motorex ® – Hydraulic Fluid 75 Shock absorber fluid (SAE 2.5) (50180751S1) Standard/classification –. Preserving materials for paints, metal and rubber Recommended supplier Motorex ® – Moto Protect Rubber grip adhesive (1) Recommended supplier KTM-Sportmotorcycle AG – GRIP GLUE Special cleaner for glossy and matte paint finishes, metal and plastic surfaces Recommended supplier Motorex ® –.

AUXILIARY SUBSTANCES Universal oil spray Recommended supplier Motorex ® – Joker 440 Synthetic. STANDARDS 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. JASO T903 MA Different technical development directions required a new specification for 4-stroke motorcycles –. INDEX fluid, changing.61 INDEX Clutch lever.12 Accessories.

INDEX Fork part number.11 raising with lift stand.39 removing from lift stand. INDEX Steering head bearing greasing. 45 Steering head bearing play adjusting.3213173en.

3213173en 04/2014 KTM-Sportmotorcycle AG 5230 Mattighofen/Austria Photo: Mitterbauer/KTM http://www.ktm.com.