. REPAIR MANUAL 2009 50 SX 50 SX Junior 50 SX Mini Article no.

1. 2012 Ktm 50 Sx Manual

KTM accepts no liability for delivery options, deviations from illustrations and descriptions, as well as misprints and other errors. Checking rear brake fluid level.59 Assembling the piston rod.31 Adding rear brake fluid.59 Assembling the damper (50 SX Junior, 50 SX Mini).32 Changing the rear brake fluid. 60 Assembling the damper (50 SX).33 Checking the rear brake linings. Removing the carburetor (50 SX).94 Removing the kickstarter idler shaft. 73 Removing the carburetor (50 SX Junior, 50 SX Mini).95 Loosening the nut of the primary gear.73 Installing the carburetor (50 SX).96 Removing the centrifugal force clutch. SERVICE SCHEDULE.137 Important maintenance work that must be done in an authorized KTM workshop.137 Important maintenance work that must be done in an authorized KTM workshop (as additional order).137 WIRING DIAGRAM.140 Wiring diagram.140 SUBSTANCES.142 AUXILIARY SUBSTANCES.

This is the Highly Detailed factory service repair manual for the 2012 Ktm 350 Sx-F Eu 350 Sx-F Cairoli Replica Eu 350 Sx-F Usa 350 Xc-F Usa has detailed. KTM #3206113. Genuine KTM REPAIR Manual on CD. 50 SX/SX MINI/SX JUNIOR. eBay!

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

Formats used The typographical and other formats used are explained below. 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 honored for damage resulting from manipulations and/or alterations to the vehicle. The engine is cold (50 SX) – Pull the choke knob fully out and turn it by max. (50 SX Junior, 50 SX Mini) – Push the choke lever up all the way. – Forcefully step on the kickstarter, pushing it all the way forward. MOTORCYCLE Vehicle level Warning Danger of accidents Modifications to the suspension settings can seriously alter the vehicle's ride behavior. – Following modifications, ride slowly at first to get the feel of the new ride behavior.

The vehicle level can be adjusted at the front by means of the clamping of the fork legs and at the rear by means of the positioning of the shock absorber. 01/FORK, TRIPLE CLAMP Cleaning dust boots of fork legs – Jack up the motorcycle. 7) – Push dust boots of both fork legs upwards.  Info The dust boots should remove dust and coarse dirt particles from the fork tubes. 01/FORK, TRIPLE CLAMP Installing the fork legs – Position the fork legs.

– Adjust fork overhang  Guideline Upper fork projection 10 17 mm (0.39 0.67 in) 300734-10 – Tighten screw  Guideline Screw, top triple clamp 25 Nm (18.4 lbf ft) –. 01/FORK, TRIPLE CLAMP – Disassemble the fork legs. 11) – Check the fork legs. 12) – Assemble the fork legs. 13) 201192-01 Disassembling the fork legs Info The operations are the same on both fork legs. The only difference between the two fork legs lies in the piston ring of the piston rod, which is only mounted on the left fork leg.

01/FORK, TRIPLE CLAMP – Pull inner tube with piston rod out of the outer tube.   Info If the damping bush remains in the outer tube, remove it as well.

 201180-10 – Remove lock ring  – Remove seal ring . 01/FORK, TRIPLE CLAMP – Measure the run-out of the inner tube. ≤ 0.10 mm (≤ 0.0039 in) Inner tube run-out » If the measured value is greater than the specified value: – Change the inner tube.

200685-10 Assembling the fork legs Info The operations are the same on both fork legs. 01/FORK, TRIPLE CLAMP – Grease and mount dust boot  Lubricant (T511) ( p. 144) 201185-10 – Refill with fork oil.

Fork oil 210 ml Fork oil (SAE 7.5) ( p. 142) (7.1 fl.

Oz.) Info Pull out and push back in the inner tube a number of times to bleed the fork leg. 01/FORK, TRIPLE CLAMP – Loosen screws on the lower triple clamp.

 – Loosen screw on the upper triple clamp.  Info Loosen the screws to the point where the fork legs can be moved without damaging it. Make the adjustments first on one fork leg and then on the other. 01/FORK, TRIPLE CLAMP – Remove nut  300739-10 – Remove protector ring  – Remove the lower triple clamp with the steering stem. – Remove the upper steering head bearing. 300740-10 Installing the lower triple clamp 4.10 – Clean the bearing and sealing elements, check for damage, and grease. Long-life grease ( p.

01/FORK, TRIPLE CLAMP – Tighten screws  Guideline Screw, bottom triple clamp 10 Nm (7.4 lbf ft) – Repeat these steps on the opposite side. – Tighten nut  Guideline Nut, steering stem M20x1.5 10 Nm (7.4 lbf ft) – Position the handlebar support. 01/FORK, TRIPLE CLAMP Checking play of steering head bearing 4.12 Warning Danger of accidents Unstable vehicle handling from incorrect steering head bearing play. – Adjust the steering head bearing play without delay. Info If the bike is ridden for a longer time with play in the steering head bearing, the bearing and the bearing seats in the frame can be damaged after time. 01/FORK, TRIPLE CLAMP – Tighten nut  Guideline Steering head nut M20x1.5 10 Nm (7.4 lbf ft) 300739-10 – Position the upper triple clamp.

– Mount nut, but do not tighten it yet.  Guideline Nut, steering stem M20x1.5 10 Nm (7.4 lbf ft) –. 02/HANDLEBAR, CONTROLS AND INSTRUMENTS Checking 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 . 02/HANDLEBAR, CONTROLS AND INSTRUMENTS – Position the handlebar clamp.

Mount and evenly tighten the four screws  Guideline Screw, handlebar clamp 20 Nm (14.8 lbf ft) Info Make sure the gap width is even. – Turn back counterclockwise by the number of clicks corresponding to the shock absorber type. Guideline Rebound damping (50 SX) Standard 10 clicks Rebound damping (50 SX Junior) Standard 12 clicks 700476-01 Rebound damping (50 SX Mini) Standard 12 clicks.  – Check the riding sag. Riding sag (50 SX) 45 55 mm (1.77 2.17 in) Riding sag (50 SX Junior) 40 50 mm (1.57 1.97 in) Riding sag (50 SX Mini) 40 50 mm (1.57 1.97 in) » If the riding sag differs from the specified measurement: –. 35 N/mm (200 lb/in) Weight of rider: 40 kg ( 88 lb.) 40 N/mm (228 lb/in) Spring rate (50 SX Junior) Weight of rider.

04/SHOCK ABSORBER, SWINGARM Adjusting seat height Warning Danger of accidents Modifications to the suspension settings can seriously alter the vehicle's ride behavior. – Following modifications, ride slowly at first to get the feel of the new ride behavior.

– Remove shock absorber. 04/SHOCK ABSORBER, SWINGARM – Release the retaining ring and adjusting ring using the special tools. Hook wrench (T304) ( p. 152) Hook wrench (T1533) ( p. 151) – Turn the retaining and adjusting rings all the way up. 200894-10 – Remove spring retainer . 04/SHOCK ABSORBER, SWINGARM – Push in seal ring retainer.

Remove lock ring   Info Do not scratch the inside surface. 300433-10 – Remove the piston rod. Drain the remaining oil. 300434-10 Disassembling the piston rod 6.13 – Disassemble the damper.

04/SHOCK ABSORBER, SWINGARM – Remove locking cap and rubber buffer   300390-10 Removing the heim joint 6.14 Condition The shock absorber has been removed. – Clamp the shock absorber into the vise using soft jaws.

– Remove collar bushing of the heim joint. 04/SHOCK ABSORBER, SWINGARM Checking the damper 6.15 Condition The damper has been disassembled. – Measure the inside diameter at both ends and in the middle of the damper car- tridge. Damper cartridge Minimum diameter 36.10 mm (1.4213 in) » If the measured value is greater than the specified value: –.

04/SHOCK ABSORBER, SWINGARM Installing the heim joint 6.16 Info The operations are the same on the upper and lower heim joints. – Place special tool underneath and press the heim joint to the middle using spe-  cial tool  Pressing tool (T1206) ( p.

04/SHOCK ABSORBER, SWINGARM Assembling the piston rod 6.17 – Clamp the piston rod with the heim joint into a vise. – Mount rubber buffer and locking cap   300410-10 – Position special tool on the piston rod.  Mounting sleeve (T313) ( p. Guideline Nut, piston rod M10x1 30 Nm (22.1 lbf ft) 300418-10 Assembling the damper (50 SX Junior, 50 SX Mini) 6.18 – Assemble the piston rod. 31) – Mount and tighten the screw of the filling port with a new sealing washer. After making adjustments, ride slowly at first to get the feel of the new ride behavior. – Turn adjusting screw to the position measured during disassembly.

 Assembling the damper (50 SX) 6.19 – Assemble the piston rod. 04/SHOCK ABSORBER, SWINGARM – Push in seal ring retainer  – Mount lock ring  Info First insert the closed part of the lock ring and then the two ends to pre- vent the surface of the damper cartridge under the groove from becoming scratched and the O-ring from being damaged during installation or opera- tion. Close the spigot and take the damper out of the special tool. – Tighten the screw of the filling port.

Guideline Screw, filling port 3 Nm (2.2 lbf ft) Installing the spring (50 SX Junior, 50 SX Mini) 6.21 – Assemble the damper. – Tension the spring to the length measured during disassembly by turning the adjusting ring. – Lock the lock nut and adjusting ring.

Installing the spring (50 SX) 6.22 – Assemble the damper. 04/SHOCK ABSORBER, SWINGARM Alternative 2 Warning Danger of accidents Modifications to the suspension settings can seri- ously alter the vehicle's ride behavior. – Extreme modifications to the adjustment of the spring elements can cause a serious deterioration in the handling characteristics and overload some components. 05/EXHAUST Removing the exhaust manifold 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 springs  Spring hooks (0) ( p. 05/EXHAUST – Remove screw  – Remove screw  700512-01 – Pull the main silencer off of the manifold at the rubber sleeve  700513-10 Installing the main silencer – Position the main silencer. – Mount the main silencer with the rubber sleeve . 05/EXHAUST Installing the glass fiber yarn filling of the main silencer – Slide the glass fiber yarn filling over the inner tube.

 – Slide the outer tube over the glass fiber yarn filling.  – Insert locking cap into the outer tube. Fit and tighten screws with tooth lock . 06/AIR FILTER Removing the air filter 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. 07/FUEL TANK, SEAT, TRIM Removing the seat – Open quick release and raise the rear of the seat.

 – Pull back the seat and remove it. 300611-10 Mounting the seat – Hook the seat onto screw and lower the seat at the rear while pushing it forward. 07/FUEL TANK, SEAT, TRIM – Raise the fuel tank. – Pull off fuel hose  Info Remaining fuel may run out of the fuel hose.

– Take off the fuel tank. 300614-10 Installing the fuel tank Danger Fire hazard Fuel is highly flammable. 08/MASK, FENDER Dismounting the front fender 10.1 – Remove screws. Remove the front fender.

 700479-10 Installing the front fender 10.2 – Position the fender with holding lugs into the drill holes on the start number  plate. 08/MASK, FENDER – Mount and tighten screw  Guideline Remaining screws, chassis 10 Nm (7.4 lbf ft) – Position the brake line.

Put the clamp on, mount and tighten screw  700468-01. 09/FRONT WHEEL Removing front wheel 11.1 – Jack up the motorcycle. 7) – Remove nut with washer.  700502-01 – Hold the front wheel and pull out the wheel spindle with the washer. Take the   front wheel out of the fork. DOT marking. The first two digits refer to the week of manufacture and last two digits refer to the year of manufac- ture.

KTM recommends that the tires be changed regardless of the actual wear, at the latest after 5 years. 09/FRONT WHEEL – 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. 10/REAR WHEEL Removing rear wheel 12.1 – Jack up the motorcycle. 7) – Remove nut  – Remove the washer  – Pull out the wheel spindle with the washer   – Remove the chain from the rear sprocket. 10/REAR WHEEL Cleaning the chain 12.4 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. 10/REAR WHEEL Checking the chain tension - installing rear wheel 12.6 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. 10/REAR WHEEL – Loosen nut  – Adjust the chain tension by turning the adjusting screws left and right.  Guideline Chain tension 5 8 mm (0.2 0.31 in) Turn adjusting screws equally on the left and right. Check that the rear wheel . 13/BRAKE SYSTEM Checking the play of the hand brake lever 13.1 – Push the hand brake lever forwards and check the play  Play of hand brake lever 3 5 mm (0.12 0.2 in) » If the play does not meet specifications: –. 13/BRAKE SYSTEM 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!. 13/BRAKE SYSTEM Info Clean up overflowed or spilt brake fluid immediately with water.

Changing the front brake fluid 13.6 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. 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. 13/BRAKE SYSTEM – Insert the brake linings. Info Ensure that the brake linings are correctly positioned in the holding spring.

700500-01 – Mount screw  – Fit the lock washer  – Install the front wheel. 46) 700501-01 Changing the front brake linings 13.10 Warning. 13/BRAKE SYSTEM Checking the free travel of the foot brake lever 13.11 Warning Danger of accidents Brake system failure.

2012 Ktm 50 Sx Manual

– If there is no free travel on the foot brake lever, pressure builds up on the rear brake circuit. The rear brake can fail due to overheating. 13/BRAKE SYSTEM – Attach the spring. – Check whether the basic position of the foot brake lever is suitable for the rider. Checking rear brake fluid level 13.14 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. 13/BRAKE SYSTEM – Jack up the motorcycle.

7) – Remove screws  – Take off cover with washer and membrane    201175-10 – Add brake fluid to level  Guideline Dimension (brake fluid level below 10 mm (0.39 in) . 13/BRAKE SYSTEM – Adjust brake fluid level up to mark  Guideline Dimension (brake fluid level below 10 mm (0.39 in)  top edge of container) Brake fluid DOT 4 / DOT 5.1 ( p. 142) – Position the cover with the membrane. Mount and tighten screws. 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. 13/BRAKE SYSTEM – Remove screws  – Take off cover with washer and membrane    – Press the brake piston back to its basic position and make sure that no brake fluid overflows from the brake fluid reservoir. Loosen the hose clamps. Detach the radiator hoses. 300618-10 – Remove the cable binder.

– Disconnect plug-in connector  300619-10 (50 SX Mini) – Detach oil line of the oil pump.  – Close the oil line using a suitable object.

30/ENGINE – Loosen both hose clamps  – Remove the carburetor and hang it to one side. Info Do not kink the throttle cable. 300622-10 – Remove screws  300623-10 – Remove nut  – Remove the swingarm pivot. 25 Nm (18.4 lbf ft) 300624-11 – Mount the carburetor. – Position and tighten hose clamps  300622-11 (50 SX Mini) – Remove the plug. – Attach oil line to the connection of the oil pump.  – Position the clamp.

30/ENGINE – Mount the radiator hoses. Position and tighten hose clamps  – Install the exhaust manifold. 38) (50 SX Mini) – Bleed the oil pump. 119) – Install the fuel tank.

30/DISASSEMBLING THE ENGINE Clamping the engine into the engine work stand 15.1 – Mount special tool on engine work stand   Engine work stand (0) ( p. 150) Fitting for work stand (0) ( p.

146) Holder of engine work stand (0) ( p. Cover the engine case opening with a cloth.

– Remove the piston pin. – Take off the piston. – Remove the upper conrod bearing.

300466-10 Removing the oil pump (50 SX Mini) 15.7 – Remove screws  – Take off the oil pump. 300467-10 Removing the alternator cover 15.8.

Take off the ignition coil and intake flange. 300469-11 – Remove reed valve housing  – Remove the gasket. 301062-10 Removing the oil pump drive gear (50 SX Mini) 15.10 – Remove lock ring  – Take off oil pump drive gear .  by screwing in the screw. Extractor (0) ( p. 148) 300477-10 (50 SX, 50 SX Junior) – Hold the rotor in place with special tool  Holding spanner, rotor (0) ( p. 30/DISASSEMBLING THE ENGINE Removing the kickstarter 15.14 – Remove screw with the washer.

 – Take off the kickstarter. 300480-10 Removing the water pump cover 15.15 – Remove screws  – Take off the water pump cover. – Remove the gasket and dowels.

300481-10 Removing the outer clutch cover 15.16. 30/DISASSEMBLING THE ENGINE Removing the kickstarter gear 15.19 – Remove kickstarter gear  301063-10 Removing the kickstarter idler shaft 15.20 – Remove kickstarter idler shaft  300489-10 Loosening the nut of the primary gear 15.21 – Hold the clutch in place with special tool . 30/DISASSEMBLING THE ENGINE Removing the clutch bearing 15.24 – Remove needle bearings and collar bushing   300486-11 Removing the primary gear 15.25 – Remove nut  – Take off primary gear  – Remove the spring washer and washer. 300494-10 Removing the left engine case 15.26. 30/DISASSEMBLING THE ENGINE – Remove engine case gasket and dowels   300499-10 Removing the transmission shafts 15.27 – Pull both transmission shafts out of the bearing seats together.

 300500-10 Removing the crankshaft 15.28 – Remove crankshaft  300501-10 –. 30/ENGINE - WORK ON INDIVIDUAL PARTS Work on the right section of the engine case 16.1 – Pull the dowels out of the engine case. – Remove crankshaft seal ring  – Warm the engine case section in an oven. Guideline 150 °C (302 °F) –. 30/ENGINE - WORK ON INDIVIDUAL PARTS – Press shaft seal ring of the countershaft from the outside to the inside with the  open side facing inward. Info The shaft seal rings must be flush on the outside. Changing the conrod bearing 16.3 –.

30/ENGINE - WORK ON INDIVIDUAL PARTS – Position the second crank web. – Position special tool with the offset facing down.  – Press the upper crank web all the way in. Info The press mandrel must be applied above the crank pin. 30/ENGINE - WORK ON INDIVIDUAL PARTS – Remove shaft seal ring  – Press out the bearing of the water pump shaft with a suitable tool. Info Support the clutch cover when pressing out. 300509-10 Installing the water pump 16.6 –.

30/ENGINE - WORK ON INDIVIDUAL PARTS Dismantling centrifugal clutch 16.8 Condition The centrifugal clutch has been removed. – Loosen screws with special tool.  Mortise key (0) ( p. 147) 300513-10 – Remove screw with spacing washer and spring  . 30/ENGINE - WORK ON INDIVIDUAL PARTS » If the clutch linings are damaged: – Replace the clutch linings. – Assemble the centrifugal clutch.

80) Checking/measuring the cylinder 16.11 – Check the cylinder bearing surface for damage. » If the cylinder bearing surface is damaged: –. 30/ENGINE - WORK ON INDIVIDUAL PARTS – Measure the piston at a distance from the piston head, at right angles to the pis-  ton pin. Guideline Distance 31.5 mm (1.24 in) 0 0 A  Piston - diameter Size 1 39.455. 30/ENGINE - WORK ON INDIVIDUAL PARTS – Change the intake flange. 30/ASSEMBLING THE ENGINE Installing the crankshaft 17.1 – Clamp the right section of the engine case into the engine work stand.

– Slide crankshaft all the way into the bearing seat of the right section of the  engine case. 300501-10 Installing the transmission shafts 17.2. 30/ASSEMBLING THE ENGINE Installing the primary gear 17.4 – Position the O-ring.

– Mount washer  – Mount spring washer. – Position primary gear  – Mount nut but do not tighten yet.  Guideline Nut, primary gear M10x1.25 40 Nm Loctite ®. 30/ASSEMBLING THE ENGINE Installing the kickstarter idler shaft 17.9 – Position the kickstarter idler shaft  300489-10 Installing the kickstarter gear 17.10 – Position kickstarter gear  Spring loop is aligned with engine case rib   300488-10 Installing the clutch drum 17.11 –. 30/ASSEMBLING THE ENGINE – Mount screw and tighten all screws in a crisscross pattern.  Guideline Screw, clutch cover M6x50 10 Nm (7.4 lbf ft) Installing the outer clutch cover 17.13 – Mount the clutch cover gasket.

– Position the outer clutch cover. Mount and tighten screws . Mount and tighten nut  Guideline Nut, rotor M10x1.25 15 Nm (11.1 lbf ft) 300475-11 (50 SX, 50 SX Junior) – Ensure that the spring washer is seated properly. – Mount rotor  300855-10 – Hold the rotor in place with the special tool. Feeler gauge (0) ( p. 150) – Tighten screws  Guideline Screw, stator clamp 6 Nm (4.4 lbf ft) 300474-10 Installing the oil pump drive gear (50 SX Mini) 17.20 – Position oil pump drive gear  – Mount lock ring  300472-11 Installing the reed valve housing, ignition coil, and intake flange 17.21.

Position the alternator cover. – Mount and tighten screws  Guideline Screw, alternator cover 6 Nm (4.4 lbf ft) 300851-11 Installing the oil pumps (50 SX Mini) 17.23 – Position the oil pump. – Mount and tighten screws  Guideline Screw, oil pump 6 Nm (4.4 lbf ft). 30/ASSEMBLING THE ENGINE Installing the piston 17.24 – Cover the engine case opening with a cloth. – Oil the conrod bearing and position it in the connecting rod. – Position the piston. Piston marking must face the exhaust side.

 300511-10 –. 30/ASSEMBLING THE ENGINE Checking the X-distance 17.26 Info The X-distance is the distance defined for the piston protrusion, when the cylinder is clamped down and the piston is at top dead center. The X-distance must be checked very carefully.

If the X-distance is too large, the compression decreases and the engine loses power. 30/ASSEMBLING THE ENGINE – Mount and tighten the spark plug. Guideline Spark plug M10x1 10 12 Nm (7.4 8.9 lbf ft) Installing the oil drain plug 17.29 – Mount and tighten the oil drain plug with magnet and the new seal ring. 31/CARBURETOR Removing the carburetor (50 SX) 18.1 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.

Detach throttle cable  – Remove the throttle slide. 300895-10 Removing the carburetor (50 SX Junior, 50 SX Mini) 18.2 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. 300901-10 – Pull back spring retainer and the throttle slide spring.  – Detach the throttle cable.

300902-10 Installing the carburetor (50 SX) 18.3 – Attach throttle cable  – Position the spring retainer and throttle slide spring. – Check the play in the throttle cable. 20) – Carburetor - adjust the idle speed. 108) 300890-11 Installing the carburetor (50 SX Junior, 50 SX Mini) 18.4 – Attach throttle cable  300903-10 – Position spring retainer . Bleed the oil pump. 119) – Check the play in the throttle cable. 20) – Carburetor - adjust the idle speed.

109) 300896-11 Checking/setting the carburetor components (50 SX) 18.5 300916-01 – Disassemble the carburetor. 99). 108) – Check the choke slide.

107) – Assemble the carburetor. 102) Checking/setting the carburetor components (50 SX Junior, 50 SX Mini) 18.6 300926-01 – Disassemble the carburetor. 101) – Check the jet needle.

31/CARBURETOR – Remove screws  – Remove the float chamber. – Remove seal. 300905-10 – Remove main jet with the washer.  300906-10 – Remove fulcrum pin  – Remove float and the float needle valve.

 300907-10 – Remove cold start jet . 31/CARBURETOR Disassembling the carburetor (50 SX Junior, 50 SX Mini) 18.8 Condition The carburetor has been removed. – Pull the fuel hose off the carburetor. 300916-10 – Remove screws  – Remove the float chamber. 300917-10 – Remove fulcrum pin . Info Make sure not to misplace the spring. 300921-10 – Pull the jet needle out of the throttle slide.

300923-10 Assembling the carburetor (50 SX) 18.9 – Mount and tighten the choke slide. Guideline Choke slide 5 Nm (3.7 lbf ft).

31/CARBURETOR Guideline Idling jet 2 Nm (1.5 lbf ft) – Mount and tighten main jet with the washer.  Guideline Main jet M5x0.75 2 Nm (1.5 lbf ft) The edge of the disk faces the float chamber.

300906-11 – Position the float needle valve and float . 31/CARBURETOR Assembling the carburetor (50 SX Junior) 18.10 Alternative 1 – Mount idle air adjusting screw with the spring.  – Set the idle air adjusting screw to the specified value. Guideline Idle air adjusting screw Open 3.5 turns Alternative 2 –. 300917-11 – Mount the fuel hose on the carburetor. 300916-10 – Position the jet needle in the throttle slide.

300923-10 Assembling the carburetor (50 SX Mini) 18.11 Alternative 1 – Mount idle air adjusting screw with the spring. 31/CARBURETOR – Mount and tighten cold start jet  Guideline Cold start jet 2 Nm (1.5 lbf ft) – Mount and tighten idling jet  Guideline Idling jet 1.5 Nm (1.11 lbf ft) – Mount and tighten main jet  300919-11 Guideline Main jet. » If the rubber sleeve is damaged or brittle, or if the lock is not functioning: – Change the choke slide. Checking the choke slide (50 SX Junior, 50 SX Mini) 18.13 Condition The choke slide has been removed. – Adjust the float level by bending float lever  300915-10 Carburetor - adjusting idle speed (50 SX) 18.19 – Screw in the idle adjusting screw until it stops and then to the prescribed basic . After changing the idling jet, start from the beginning with the adjusting steps.

Following extreme air temperature or altitude changes, adjust the idle speed again. Carburetor - adjusting idle speed (50 SX Junior, 50 SX Mini) 18.20 – Screw in idle air adjusting screw all the way and turn it to the specified basic . 31/CARBURETOR Info If the speed rise is too high, reduce the idle speed to a normal level and repeat the preceding 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.

32/CLUTCH Removing the centrifugal force clutch 19.1 – Remove nut  – Disconnect spring  – Take off the foot brake lever. 300654-10 – Lay the motorcycle on its side. – Remove screws  – Take off the clutch cover.

32/CLUTCH – Position the clutch drum. – Hold the clutch drum with the special tool  – Mount and tighten screw  Guideline Screw, clutch drum 30 Nm Loctite ® 243™ (22.1 lbf ft) 300656-11 – Position the clutch cover with the gasket. 32/CLUTCH – Correct the washer according to the measured value.  Guideline A washer of 0.2 mm (0.008 in) 100 rpm changes the clutch engagement speed by about: Info The spacing washer of 1.7 mm (0.067 in) must always be fitted. 35/WATER PUMP, COOLING SYSTEM Draining the coolant 20.1 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. 35/WATER PUMP, COOLING SYSTEM – Make a short test ride. – Check the coolant level. 115) Checking the coolant level 20.3 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. 35/WATER PUMP, COOLING SYSTEM – Check the coolant level in the radiator.

Coolant level above the radiator fins 10 mm (0.39 in)  » If the coolant level does not meet specifications: – Correct the coolant level. Alternative 1 Coolant ( p. 38/LUBRICATION SYSTEM Changing the gear oil 21.1 – Drain the gear oil. 117) 400721-01 – Fill up with gear oil. 117) 400722-01 Draining the gear oil 21.2 Warning Danger of scalding Engine oil and gear oil get very hot when the motorcycle is ridden. 38/LUBRICATION SYSTEM – Remove screw cap and fill up with gear oil.  Gear oil 0.20 l (0.21 qt.) Gear oil (ATF Dexron 3) ( p.

142) – Mount and tighten screw cap. Danger Danger of poisoning Exhaust gases are poisonous and inhaling them may result in unconsciousness and/or death. – Start the engine and check that it is oil-tight. Filling up with oil (50 SX Mini) 21.6 Warning Engine failure If the vehicle is run without 2-stroke oil in the tank, the result is engine failure. 38/LUBRICATION SYSTEM – Remove screws  – Take off the oil pump. – Pull off oil line from the carburetor.  300651-10 – Turn the oil pump gear counterclockwise until oil flows out of oil line without   bubbles.

39/IGNITION SYSTEM Checking the ignition system 22.1 Warning Risk of injury The ignition system is under high voltage. – To avoid the danger of an electric shock, do not touch metal parts and the ends of the connection cable during and imme- diately after measuring.

39/IGNITION SYSTEM – Measure high voltage output of ignition coil against ground. Ignition coil Resistance of secondary winding 2.025 2.475 kΩ at: 20 °C (68 °F) » If the measured value differs from the setpoint value: – Change the ignition coil. – Fuel feed interrupted Check the fuel tank breather. – Clean the fuel tap. (50 SX Junior, 50 SX Mini) – Check/set the carburetor components. 99) (50 SX) – Check/set the carburetor components.

121) – Engine has too little power Fuel feed interrupted Check the fuel tank breather. – Clean the fuel tap.

(50 SX Junior, 50 SX Mini) – Check/set the carburetor components. 99) (50 SX) – Check/set the carburetor components. Needle bearing Piston pin bearing Needle bearing Pistons Aluminum cast Piston rings 1 rectangular ring Engine lubrication (50 SX, 50 SX Junior) Mixture oil lubrication Engine lubrication (50 SX Mini) Separate lubrication Primary transmission 61:33 straight cut spur gear Clutch. TECHNICAL DATA - TOLERANCE, WEAR LIMITS OF ENGINE ≥ 98.00 mm (≥ 3.8583 in) Clutch shoe height Piston - diameter Size 1 39.455 39.465 mm (1.55334 1.55374 in) Size 2 39.465 39.475 mm (1.55374 1.55413 in) Piston/cylinder - mounting clearance New condition 0.042. TECHNICAL DATA - ENGINE TIGHTENING TORQUES ® Screw, kickstarter 6 Nm (4.4 lbf ft) Loctite 243™ – Screw, oil pump (50 SX Mini) 6 Nm (4.4 lbf ft) – Screw, stator clamp 6 Nm (4.4 lbf ft) ® Screw, water pump wheel 5 Nm (3.7 lbf ft). Open 3 turns Main jet Jet needle Idling jet Needle jet 260AU Throttle slide Cold start jet 50 SX Junior 27.2 Carburetor type Dell`Orto PHVA 14DS Needle position 3rd position from top Idle air adjusting screw Open 3.5 turns Main jet.

Ground clearance unloaded (50 SX Junior) 220 mm (8.66 in) Ground clearance unloaded (50 SX Mini) 184 mm (7.24 in) Weight without fuel, approx. (50 SX) 39.8 kg (87.7 lb.) Weight without fuel, approx. (50 SX Junior, 50 SX Mini) 39.0 kg (86 lb.). 2.75 - 10 37J TT Pirelli SCORPION MX Mid Soft 32 NHS Pirelli SCORPION MX Mid Soft 32 NHS (50 SX Junior, 50 SX Mini) 2.50 - 10 33J TT 2.75 - 10 37J TT Pirelli SCORPION MX Mid Soft 32 NHS.

100±2.5 mm (3.94±0.098 in) Fork length 692 mm (27.24 in) Fork oil 210 ml (7.1 fl. Oz.) Fork oil (SAE 7.5) ( p.

142) 50 SX Junior 29.2 Fork part number 3 Marzocchi Fork Spring rate Weight of rider: 25 35 kg (55 77 lb.). 45 55 mm (1.77 2.17 in) Fitted length 275 mm (10.83 in) Shock absorber oil Shock absorber oil (SAE 2.5) (50180342S1) ( p. 143) 50 SX Junior 30.2 Shock absorber part number 03.18.9E.01 Shock absorber WP Suspension 3614 BAEM Rebound damping. TECHNICAL DATA - SHOCK ABSORBER Riding sag 40 50 mm (1.57 1.97 in) Fitted length 245 mm (9.65 in) Shock absorber oil Shock absorber oil (SAE 2.5) (50180342S1) ( p.

143). TECHNICAL DATA - TIGHTENING TORQUES FOR CHASSIS – Spoke nipple M3.5 3 Nm (2.2 lbf ft) ® Rear brake caliper screw 10 Nm (7.4 lbf ft) Loctite 243™ – Remaining nuts, chassis 15 Nm (11.1 lbf ft) – Screw, ball joint of push rod on foot 10 Nm (7.4 lbf ft) brake cylinder –. CLEANING/CONSERVATION Cleaning motorcycle 32.1 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. Check the tire air pressure.

47) – 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. Clean and grease adjusting screws of chain adjuster. S20A: Every 20 operating hours S40A: Every 40 operating hours Important maintenance work that must be done in an authorized KTM workshop (as additional order) 34.2 S20A S40A S80A Check/set the carburetor components. (50 SX Junior, 50 SX Mini) ( p.

SERVICE SCHEDULE S20A S40A S80A Check radial clearance of conrod bearing. Change crankshafts and conrod bearings. Service the fork. 10).

Service the shock absorber. 25). Clean and lubricate swingarm bearing. WIRING DIAGRAM Wiring diagram 35.1 300929-01. WIRING DIAGRAM Components Kill switch Alternator Ignition coil Cable colors black Black. 2-stroke engine oil According to – JASO FC ( p. 153) Guideline – ® Only use high quality 2-stroke engine oil of a well-known brand.

KTM recommends Motorex products. Fully synthetic Supplier ® Motorex – Cross Power 2T Brake fluid DOT 4 / DOT 5.1 According to –. SUBSTANCES Shock absorber oil (SAE 2.5) (50180342S1) According to – SAE ( p. 153) (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 (ROZ 95 / RON 95 / PON 91) According to –. AUXILIARY SUBSTANCES Air filter cleaner Guideline – ® KTM recommends Motorex products.

Supplier ® Motorex – Twin Air Dirt Bio Remover Carburetor cleaner Guideline – ® KTM recommends Motorex products. Supplier ® Motorex – Carburetor Chain cleaner Guideline – ®. AUXILIARY SUBSTANCES Lubricant (T625) Guideline – ® KTM recommends Molykote products. Supplier ® Molykote – 33 Medium Motorcycle cleaner Guideline – ® KTM recommends Motorex products.

Supplier ® Motorex – Moto Clean 900 Off-road chain spray Guideline – ® KTM recommends Motorex products. SPECIAL TOOLS Adjustment gauge Art. No.: 0 301086-01 Tachometer Art. No.: 0 400044-01 Fitting for work stand Art. No.: 0 400576-01 Holder of engine work stand Art.

No.: 0 300673-01 Bushing, crankshaft pressing device Art. No.: 1 300991-01. SPECIAL TOOLS Holding spanner, rotor Art. No.: 0 300669-01 Mortise key Art. No.: 0 300671-01 Press plate Art. No.: 0 301066-10 Extractor Art. No.: 0 300937-10 Gear segment Art.

No.: 0 300670-01. SPECIAL TOOLS Protecting sleeve Art. No.: 0 300936-10 Extractor Art. No.: 0 400045-01 Anchor plate Art. No.: 2 300939-10 Spring hooks Art. No.: 0 400363-01 Pressing device, crankshaft, complete Art. No.: 0 300940-10.

SPECIAL TOOLS Bleed syringe Art. No.: 0 400058-01 Holding spanner Art. No.: 0 300676-01 Work stand Art. No.: 0 500071-01 Peak voltage adapter Art. No.: 0 400083-01 Torque wrench with various accessories in set Art. No.: 0 200910-10.

SPECIAL TOOLS Feeler gauge Art. No.: 0 400110-01 Engine work stand Art. No.: 0 200306-01 Hook wrench Art.

No.: T106S 301085-01 Art. No.: T120 201235-10 Pressing tool Art. No.: T1206 200583-10. SPECIAL TOOLS Pressing tool Art. No.: T1207S 200585-01 Pressing tool Art. No.: T129 200584-01 Squeeze bottle Art.

No.: T137S 201187-10 Hook wrench Art. No.: T1533 301085-01 Nitrogen filling tool Art.

No.: T170S1 300574-10. SPECIAL TOOLS Hook wrench Art. No.: T304 301085-01 Mounting sleeve Art. No.: T313 300578-10. 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.

The SAE viscosity classes were defined by the Society of Automotive Engineers and are used for classifying oils according to their vis- cosity. INDEX rear brake, changing.62 INDEX rear brake, checking.61 Air filter rear brake, installing.

INDEX oil pump, removing.69 removing. 42 outer clutch cover, removing. INDEX Rebound damping Tire air pressure shock absorber, adjusting.

22 checking. 47 Riding sag Tire condition adjusting.3206060en.

3206060en KTM-Sportmotorcycle AG 5230 Mattighofen/Austria http://www.ktm.com.

. OWNER'S MANUAL 2013 50 SX 50 SX Mini Art. KTM accepts no liability for delivery options, deviations from illustrations and descriptions, as well as misprints and other errors.

TABLE OF CONTENTS 10 TUNING THE CHASSIS.23 TABLE OF CONTENTS MEANS OF REPRESENTATION.4 10.1 Adjusting the rebound damping of the shock Symbols used. 4 absorber.23 Formats used. 4 10.2 Measuring rear wheel sag unloaded.23 SAFETY ADVICE. TABLE OF CONTENTS 12.4 Checking brake discs.46 19 TROUBLESHOOTING.74 12.5 Checking front brake fluid level.46 20 TECHNICAL DATA.76 12.6 Adding front brake fluid.47 20.1 Engine.76 12.7 Checking the front brake linings. 48 20.2 Engine tightening torques. All work marked with this symbol requires specialist knowledge and technical understanding.

In the interest of the safety of your child, have these jobs performed in an authorized KTM workshop. There, your motorcycle will be serviced optimally by specially trained experts using the specialist tools required. SAFETY ADVICE Use definition - intended use KTM sport motorcycles are designed and built to withstand the normal stresses and strains of competitive use. The motorcycles com- ply 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 record and in the KTM dealer.net; otherwise, all warranty claims will be void. No warranty claims can be considered for damage resulting from manipulations and/or alterations to the vehicle. VIEW OF VEHICLE View of the vehicle from the left front (example) 601973-10 Filler cap Quick release of seat Fuel tap ( p. 13) Choke ( p. 14) Plug-in stand ( p. 14) Chain guide.

VIEW OF VEHICLE View of the vehicle from the right rear (example) 601972-10 Kill switch ( p. 12) Throttle grip ( p. 12) Hand brake lever ( p. 12) Chassis number ( p. 10) Shock absorber rebound adjustment Level viewer for brake fluid, rear Foot brake lever ( p. SERIAL NUMBERS Chassis number The chassis number is stamped on right of the steering head.

601576-10 Type label (50 SX) The type label is located on the front frame tube. S00010-10 (50 SX Mini) The type label is located on the frame at the front right. S00009-10 Engine number The engine number.

SERIAL NUMBERS Shock absorber part number The shock absorber part number is stamped on the top of the shock absorber above the adjusting ring towards the rear. CONTROLS Hand brake lever Hand brake lever is fitted on the right side of the handlebar. The hand brake lever is used to activate the front brake. 601578-10 Throttle grip Throttle grip is fitted on the right side of the handlebar. 601577-10 Kill switch Kill switch. CONTROLS – Turn the tank cap counterclockwise and pull it up.

601580-10 Closing filler cap – Put the tank cap on and turn it clockwise. Info Run the fuel tank breather hose without kinks. 601580-11 Opening oil tank cap (50 SX Mini) –. CONTROLS Choke (50 SX) The choke knob is fitted on the left of the carburetor. Activating the choke function frees an opening through which the engine can draw extra fuel. This results in a richer fuel-air mixture, which is needed for a cold start.

Info If the engine is warm, the choke function must be deactivated. 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 Info To give your child a feel for the brake system, you should push your child at first. Do not start the engine until your child is able to apply the necessary front brake pressure.

Initially, let your child drive to another person who can help your child stop and turn. RIDING INSTRUCTIONS Checks and maintenance measures when preparing for use Info Before each use, check the condition of the vehicle and its operating safety.

The vehicle must be in perfect technical condition when it is being operated. – Check the gear oil level. Open the throttle carefully. Riding Info If you hear unusual noises while riding, stop immediately, switch off the engine, and contact an authorized KTM workshop.

– If the choke function was activated, deactivate it after the engine has warmed up. RIDING INSTRUCTIONS – 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. RIDING INSTRUCTIONS – Fill the fuel tank with fuel up to measurement 0 0 0 Guideline Measurement of 35 mm (1.38 in) Fuel tank 2.0 l (2.1 qt.) Super unleaded (ROZ 95/RON 95/PON capacity, approx.

82) (50 SX Mini) Fuel tank 2.3 l (2.4 qt.) Super unleaded gasoline, mixed with. SERVICE SCHEDULE Service schedule S10N S20A S40A S80A Check the front brake linings. 48). Check the rear brake linings. 52). Check the brake discs.

Create a service entry in the KTM DEALER.NET and in the service record. S10N: Once after 10 operating hours S20A: Every 20 operating hours S40A: Every 40 operating hours S80A: Every 80 operating hours J1A: Annually. 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.) – Turn adjusting screw clockwise up to the last perceptible click. Adjusting the spring preload 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.) Preparatory work –. TUNING THE CHASSIS 10.6 Adjusting the riding sag Preparatory work – Raise the motorcycle with a lift stand. 27) – Remove shock absorber. 34) – After removing the shock absorber, clean it thoroughly. Main work – Choose and mount a suitable spring.

Guideline Spring rate (50 SX) Weight of rider: 15. TUNING THE CHASSIS – Remove the four screws.

Remove the handlebar clamps. Remove the handlebar 0 0 1 and lay it to one side. Info 0 0 2 Protect the motorcycle and its attachments from damage by covering them. Do not bend the cables and lines. MAINTENANCE WORK ON THE CHASSIS 11.1 Raising the motorcycle with a 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 tires should no longer be in contact with the ground. MAINTENANCE WORK ON THE CHASSIS 11.4 Removing the fork protector – Remove screws. Take off clamp – Remove screws on the left fork leg. Take off the fork protector.

700431-01 – Remove screws on the right fork leg. Take off the fork protector. 700432-01 11.5 Installing the fork protector. MAINTENANCE WORK ON THE CHASSIS – Loosen screws.

Remove the left fork leg. – Loosen screws. Remove the right fork leg. 601594-10 11.7 Installing the fork legs Main work – Position the fork legs. Info The upper milled groove in the fork leg must be flush with the top edge of the upper triple clamp. MAINTENANCE WORK ON THE CHASSIS – Remove protective ring – Remove the lower triple clamp with the steering stem.

– Remove the upper steering head bearing. 601605-10 11.9 Installing the lower triple clamp Main work – Clean the bearing and sealing elements, check for damage, and grease.

High viscosity grease ( p. 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.

MAINTENANCE WORK ON THE CHASSIS Main work – 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: –. MAINTENANCE WORK ON THE CHASSIS 11.13 Dismounting the start number plate – Remove screw and take off clamp. – Remove screw. Remove the start number plate. C00050-10 11.14 Installing the start number plate – Position the start number plate with the drill holes onto the holding lugs of the fender.

MAINTENANCE WORK ON THE CHASSIS – Position the front fender. Mount and tighten screws Guideline Remaining screws, chassis 10 Nm (7.4 lbf ft) 601982-11 11.17 Removing the shock absorber Preparatory work – Raise the motorcycle with a lift stand. MAINTENANCE WORK ON THE CHASSIS 11.20 Mounting the seat – Hook the seat onto screw and lower the seat at the rear while pushing it forward.

Projection hooks into the fuel tank. 601977-10 – Close quick release 601976-11 11.21 Removing the air filter Note Engine failure Unfiltered intake air has a negative effect on the service life of the engine. MAINTENANCE WORK ON THE CHASSIS 11.23 Cleaning the air filter and air filter box 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. MAINTENANCE WORK ON THE CHASSIS 11.25 Installing the main silencer – Position the main silencer. – Mount the main silencer with the rubber sleeve – Mount the silentblock with the screw Guideline Remaining screws, chassis 10 Nm (7.4 lbf ft) 700513-01 –.

MAINTENANCE WORK ON THE CHASSIS 11.28 Installing the chain guard (50 SX) – Position the chain guard. Mount cable binder Info The cable binder must be run between chain sliding guard swingarm 100816-10 – Mount the cable binder at the rear. MAINTENANCE WORK ON THE CHASSIS Main work – Check the chain for coarse dirt accumulation. » If the chain is very dirty: – Clean the chain.

39) 400678-01 Finishing work (50 SX) – Install the chain guard. MAINTENANCE WORK ON THE CHASSIS Main work – Push the chain at the end of the chain sliding component upward to measure the chain tension Info The upper chain section must be taut. Because chain wear is not always even, repeat this measurement at differ- ent chain positions. MAINTENANCE WORK ON THE CHASSIS Main work – Check the engine sprocket cover for wear. » If the engine sprocket cover is worn through in the marked area – Change the engine sprocket cover.

100896-10 – Check the rear sprocket and engine sprocket for wear. MAINTENANCE WORK ON THE CHASSIS – Check the chain sliding piece for wear. » If the lower edge of the chain pins is in line with or below the chain sliding piece: – Change the chain sliding piece. – Check the chain sliding piece for tightness. 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. 601599-01 11.38 Checking the swingarm –. MAINTENANCE WORK ON THE CHASSIS 11.40 Checking the rubber grip – Check the rubber grips on the handlebar for damage, wear, and looseness. » If a rubber grip is damaged, worn, or loose: – Change and secure the rubber grip. Rubber grip adhesive (1) ( p.

BRAKE SYSTEM 12.1 Checking play of handbrake lever – Push the handbrake lever forwards and check the play Play of hand brake lever 3 5 mm (0.12 0.2 in) » If the play does not meet specifications: – Adjust the play of the hand brake lever. 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. 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 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. 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 Guideline Brake fluid level under top level of con- 5 mm (0.2 in) tainer Brake fluid DOT 4 / DOT 5.1 ( p.

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

Info Clean up overflowed or spilt brake fluid immediately with water. 12.11 Checking the free travel of the foot brake lever Warning. 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.) – Stand the vehicle upright. 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 ≥ 1 mm (≥ 0.04 in) Minimum thickness ». 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. 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.

WHEELS, TIRES 13.1 Removing the front wheel Preparatory work – Raise the motorcycle with a lift stand. 27) Main work – Remove screw – Loosen screws 601596-10 – Withdraw the wheel spindle while holding the front wheel. Take the front wheel out of the fork. Checking the tire condition Info Only mount tires that have been approved and/or recommended by KTM. Other tires could have a negative effect on riding behavior. The type, condition and air pressure of the tires all have an important impact on the riding behavior 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 can cause wheel imbalance, which leads to more loose spokes in a short time. WHEELS, TIRES » If the spoke tension differs: – Correct the spoke tension.

– Check the spoke torque. Guideline Spoke nipple M3.5 3 Nm (2.2 lbf ft) Torque wrench with various accessories in set (0). COOLING SYSTEM 14.1 Cooling system The water pump in the engine forces the coolant to flow. The pressure resulting from the warming of the cooling system is regulated by a valve in the radiator cap. This ensures that operating the vehicle at the specified coolant temperature will not result in a risk of malfunctions. COOLING SYSTEM 14.3 Checking 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. COOLING SYSTEM 14.5 Refilling coolant Warning Danger of poisoning Coolant is poisonous and a health hazard. – Avoid contact between coolant and skin, eyes and clothing. If it gets into your eyes, rinse immediately with water and con- tact a doctor. Wash affected skin areas immediately with soap and water.

If coolant is swallowed, contact a doctor immedi- ately. TUNING THE ENGINE 15.1 Checking the installation position of the throttle grip – Position the throttle grip so that surface is vertical. Info If the throttle grip is tipped forward, the throttle cable will slip out of the guide on the carburetor. The throttle slide can no longer be closed.

601970-10 15.2 Checking the play of the throttle cable. TUNING THE ENGINE 15.4 Carburetor - idle (50 SX) The idle setting of the carburetor has a big influence on the starting behavior, stable idling and the response to throttle opening. That 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 Info If the speed rise is too high, reduce the idle speed to a normal level and repeat the preceding 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 adjusting screw to the end without any change of engine speed, you have to install a smaller idling jet. TUNING THE ENGINE 15.8 Emptying the carburetor float chamber 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.

TUNING THE ENGINE – Read the speed. Slip speed 8,700 9,300 rpm » If the specified value is not reached: – Adjust the clutch. 66) 15.10 Removing the clutch cover Warning Environmental hazard Improper handling of fuel is a danger to the environment. TUNING THE ENGINE Info The springs may not be pretensioned by more than 17 clicks from the stop using the adjusting screws. Condition If the slip speed is too low: – Turn adjusting screws clockwise. Guideline 1 click increases the slip speed by 250.

SERVICE WORK ON THE ENGINE 16.1 Checking oil level (50 SX Mini) Preparatory work – Stand the motorcycle upright on a horizontal surface. Main work – Check the oil level in the oil tank.

For a full fuel tank, the oil tank must be filled up to MIN mark at a minimum. SERVICE WORK ON THE ENGINE – Turn the oil pump gear counterclockwise until oil flows out of oil line without bubbles. 300653-10 – Connect oil line – Position the oil pump. – Mount and tighten screws Guideline Screw, oil pump 6 Nm (4.4 lbf ft) 300651-10 16.3. SERVICE WORK ON THE ENGINE 16.5 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 – Remove gear oil level check screw S00005-10 – Remove screw cap. Stand the vehicle upright. – Add gear oil until it flows out of the bore of the gear oil level screw. Gear oil (ATF Dexron 3) ( p. CLEANING, CARE 17.1 Cleaning 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. 57) – Store the vehicle in a dry location that is not subject to large fluctuations in tem- perature.

Info KTM recommends raising the motorcycle. – Raise the motorcycle with a lift stand.

27) – Cover the vehicle with a tarp or similar cover that is permeable to air. TROUBLESHOOTING Faults Possible cause Action – Engine turns but does not start Operating error Go through the steps of starting the engine. 17) – Motorcycle was out of use for a long Empty the carburetor float chamber. Time and there is old fuel in the float p. TROUBLESHOOTING Faults Possible cause Action – Engine has too little power Exhaust system leaky, deformed or Check exhaust system for damage.

Too little glass fiber yarn filling in – Change the glass fiber yarn filling of the main main silencer silencer. TECHNICAL DATA 20.1 Engine Design 1-cylinder 2-stroke engine, water-cooled, with reed intake Displacement 49.0 cm³ (2.99 cu in) Stroke 40 mm (1.57 in) Bore 39.5 mm (1.555 in) Crankshaft bearing 2 grooved ball bearings Conrod bearing Needle bearing Piston pin bearing Needle bearing Pistons Aluminum cast. TECHNICAL DATA 20.3 Carburetor with carburetor tuning 20.3.1 50 SX Carburetor type Dell`Orto PHBG 19BS Needle position 3rd position from top Idle mixture adjusting screw Open 3 turns Main jet Jet needle Idling jet Needle jet 260AU Throttle slide Cold start jet 20.3.2 50 SX Mini Carburetor type. 2.50 - 10 33J TT 2.75 - 10 37J TT Pirelli SCORPION MX Mid Soft 32 NHS Pirelli SCORPION MX Mid Soft 32 NHS Additional information is available in the Service section under: 20.7 Fork 20.7.1 50 SX Mini Fork part number 07.18.1L.01. TECHNICAL DATA 20.7.2 50 SX Fork part number 07.18.1L.03 Fork WP Suspension USD 35 Fork length 685 mm (26.97 in) Spring rate Weight of rider: 15 25 kg (33 55 lb.) 1.8 N/mm (10.3 lb/in) Weight of rider (standard): 25 35 kg (55 77 lb.) 2.0 N/mm (11.4 lb/in) Weight of rider: 35.

TECHNICAL DATA 20.9 Chassis tightening torques – Spoke nipple M3.5 3 Nm (2.2 lbf ft) – Screw, brake linings 8 Nm (5.9 lbf ft) ® Rear brake caliper screw 10 Nm (7.4 lbf ft) Loctite 243™ – Remaining nuts, chassis 10 Nm (7.4 lbf ft) –. SUBSTANCES 2-stroke engine oil According to – JASO FC ( p. 85) Guideline – Only use high quality 2-stroke engine oil of a well-known brand.

KTM recommends Motorex ® products. Fully synthetic Supplier Motorex ® – Cross Power 2T Brake fluid DOT 4 / DOT 5.1 According to –. SUBSTANCES Shock absorber oil (SAE 2.5) (50180342S1) According to – SAE ( p. 85) (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 (ROZ 95/RON 95/PON 91) According to –. AUXILIARY SUBSTANCES 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 Cleaning and preserving materials for metal, rubber and plastic Guideline –. AUXILIARY SUBSTANCES Oil for foam air filter Guideline – KTM recommends Motorex ® products. Supplier Motorex ® – Twin Air Liquid Bio Power Rubber grip adhesive (1) Supplier KTM-Sportmotorcycle AG – GRIP GLUE Universal oil spray Guideline – KTM recommends Motorex ®. 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. The SAE viscosity classes were defined by the Society of Automotive Engineers and are used for classifying oils according to their vis- cosity. INDEX Coolant INDEX draining.

60 Accessories.7 refilling. INDEX Gear oil level Rebound damping checking.

69 shock absorber, adjusting. INDEX Tire condition checking. 56 Transport.19 Troubleshooting.3211854en. 3211854en 05/2012 KTM-Sportmotorcycle AG 5230 Mattighofen/Austria Photo: Mitterbauer/KTM http://www.ktm.com.