CONTENTS 07/FUEL TANK, SEAT, TRIM..........42 CONTENTS MEANS OF REPRESENTATION ..........5 Removing the seat ............42 IMPORTANT NOTES ............6 Mounting the seat ............42 MOTORCYCLE..............7 Removing the fuel tank ..........42 Jacking up the motorcycle ..........7 Installing the fuel tank ...........
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CONTENTS Removing the alternator cover......... 69 Installing the alternator cover ......... 90 Removing the ignition coil, intake flange, and reed valve Installing the oil pumps (50 SX Mini) ......90 housing ................ 70 Installing the piston............90 Removing the oil pump drive gear (50 SX Mini)....70 Installing the cylinder ............
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SERVICE SCHEDULE............134 Important maintenance work that must be done in an authorized KTM workshop ..........134 Important maintenance work that must be done in an authorized KTM workshop (as additional order)....134 WIRING DIAGRAM ............136 Wiring diagram............136 SUBSTANCES..............138 AUXILIARY SUBSTANCES..........
All work marked with this symbol requires specialist knowledge and technical understanding. In the interest of your own safety, have these jobs done in an authorized KTM workshop! There, your motorcycle will be serviced optimally by specially trained experts using the specialist tools required.
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.
MOTORCYCLE Jacking up the motorcycle Note Danger of damage The parked vehicle may roll away or fall over. – Always place the vehicle on a firm and even surface. – Jack up the motorcycle underneath the engine. Work stand (54829055000) ( p.
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. ( p. 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 – Disassemble the fork legs. ( p. 11) – Check the fork legs. ( p. 12) – Assemble the fork legs. ( p. 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. 140) 201185-10 – Refill with fork oil. Fork oil 210 ml Fork oil (SAE 7.5) ( p. 138) (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 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.
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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 ...
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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.
04/SHOCK ABSORBER, SWINGARM Adjusting the rebound damping of the shock absorber Danger Danger of accidents Disassembly of pressurized parts can lead to injury. – The shock absorber is filled with high density nitrogen. Adhere to the description provided. – Turn adjusting screw clockwise up to the last perceptible click.
04/SHOCK ABSORBER, SWINGARM Checking the riding sag of the shock absorber – Measure distance of rear wheel unloaded. ( p. 22) – Hold the motorcycle in a vertical position and seat the rider, wearing a full set of protective clothing, on the motorcycle in the normal sitting position (feet on the footrests).
04/SHOCK ABSORBER, SWINGARM Adjusting the riding sag – Remove shock absorber. ( p. 24) – After removing the shock absorber, clean it thoroughly. – Choose and mount a suitable spring. Guideline Spring rate (50 SX) Weight of rider: < 25 kg (< 55 lb.) 30 N/mm (171 lb/in) Weight of rider: 25…...
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. ( p.
04/SHOCK ABSORBER, SWINGARM – Release the retaining ring and adjusting ring using the special tools. Hook wrench (T304) ( p. 148) Hook wrench (T1533) ( p. 147) – 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. ( p.
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.
04/SHOCK ABSORBER, SWINGARM – Pull out the piston rod until the seal ring retainer rests against the lock ring. – Mount locking cap with a plastic hammer. – Fill the damper with nitrogen. ( p. 34) 300444-10 Alternative 1 –...
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.
04/SHOCK ABSORBER, SWINGARM – Connect the filling cylinder to connector Filling gas - nitrogen – Adjust pressure regulator Guideline Gas pressure 10 bar (145 psi) – Position the damper in the special tool. The hexagonal part of tap handle engages in the hexagon socket of the fill- ...
04/SHOCK ABSORBER, SWINGARM Alternative 1 – Tension the spring to the defined length by turning the adjusting ring. Guideline Spring preload Standard 3 mm (0.12 in) Hook wrench (T304) ( p. 148) Hook wrench (T1533) ( p. 147) Alternative 2 200893-10 Warning Danger of accidents Modifications to the suspension settings can seri-...
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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 (50305017000) ( 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. 700480-01 –...
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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. ( p. 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. ( p. 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. ( p. 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. – 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. ( p. 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. 138) – 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.
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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. –...
30/ENGINE Removing the engine 14.1 – Remove the fuel tank. ( p. 42) – Drain the coolant. ( p. 112) – Jack up the motorcycle. ( p. 7) – Remove the exhaust manifold. ( p. 38) – Loosen the hose clamps. Detach the radiator hoses. 300618-10 –...
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. 300624-10 –...
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30/ENGINE – Mount and tighten nuts of the swingarm pivots. Guideline Nut, swingarm pivot 45 Nm (33.2 lbf ft) – Fully tighten screw Guideline Engine carrying screw 25 Nm (18.4 lbf ft) 300624-11 – Mount the carburetor. – Position and tighten hose clamps ...
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30/ENGINE – Mount the radiator hoses. Position and tighten hose clamps – Install the exhaust manifold. ( p. 38) (50 SX Mini) – Bleed the oil pump. ( p. 117) – Install the fuel tank. ( p. 43) – Refill the coolant.
30/DISASSEMBLING THE ENGINE Clamping the engine into the engine work stand 15.1 – Mount special tool on engine work stand Engine work stand (61229001000) ( p. 146) Fitting for work stand (45229001060) ( p. 142) Holder of engine work stand (45229001070) ( p.
30/DISASSEMBLING THE ENGINE Removing the cylinder 15.5 – Remove nuts on both sides. – Carefully slide the cylinder up and take it off. – Take off the cylinder base gasket. 300464-10 Removing the piston 15.6 – Remove piston pin retainer ...
30/DISASSEMBLING THE ENGINE – Remove distance sleeve 300476-10 – Mount special tool on the rotor, apply counterpressure, and pull off the rotor by screwing in the screw. Extractor (46129021000) ( p. 144) 300477-10 (50 SX) – Hold the rotor in place with special tool ...
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 Centrifugal clutch removed. – Loosen screws with special tool. Mortise key (45229021000) ( p. 143) 300513-10 Clutch spring with green mark – Remove screw with spacing washer and spring ...
30/ENGINE - WORK ON INDIVIDUAL PARTS – Tighten screws with special tool. Guideline Screw, clutch spring 7 Nm (5.2 lbf ft) Mortise key (45229021000) ( p. 143) 300513-11 Checking/measuring clutch 16.10 Condition The centrifugal clutch has been removed. – Measure clutch.
30/ENGINE - WORK ON INDIVIDUAL PARTS Checking/measuring the piston 16.12 – Check the piston bearing surface for damage. » If the piston bearing surface is damaged: – Change the piston and, if necessary, the cylinder. – Check that the piston ring moves smoothly in the piston ring groove. »...
30/ENGINE - WORK ON INDIVIDUAL PARTS Checking the piston ring end gap 16.14 – Remove the piston ring from the piston. 0 0 B – Place the piston ring in the cylinder and align it with the piston. Guideline Under the upper edge of the cylinder 10 mm (0.39 in) –...
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 ...
30/ASSEMBLING THE ENGINE Installing the rotor 17.17 (50 SX Mini) – Ensure that the spring washer is seated properly. – Mount rotor 300478-10 – Mount distance sleeve 300476-11 – Hold the rotor in place with the special tool. Holding spanner, rotor (45229012000) ( p.
30/ASSEMBLING THE ENGINE Installing the stator 17.18 – Position the stator. – Mount screws but do not tighten yet. Guideline Screw, stator clamp 6 Nm (4.4 lbf ft) – Position cable support sleeve 300473-11 Adjusting the stator/rotor distance 17.19 –...
30/ASSEMBLING THE ENGINE – Slide piston pin into the connecting rod by hand. 300466-11 – Position the piston pin retainer in the 6 o'clock or 12 o'clock position. – Ensure that the piston pin retainer is correctly seated on both sides. –...
30/ASSEMBLING THE ENGINE X-distance (distance from adjusting 0… 0.10 mm (0… 0.0039 in) gauge to piston) » If the specified value is not reached: – Set the X-distance. ( p. 92) Setting the X-distance 17.27 Info The X-distance is adjusted by inserting cylinder base gaskets of various thicknesses. –...
30/ASSEMBLING THE ENGINE Refilling with gear oil 17.30 – Remove screw cap and refill with gear oil. Gear oil 0.20 l (0.21 qt.) Gear oil (ATF Dexron 3) ( p. 138) – Mount and tighten the screw cap. 300529-10 Mounting the spark plug connector 17.31 –...
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. –...
31/CARBURETOR – Pull back the spring retainer and throttle slide spring. – Detach throttle cable – Remove the throttle slide. 300895-10 Removing the carburetor (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.
31/CARBURETOR – Unscrew hose clip – Pull the carburetor out of the intake flange. – Pull the carburetor forward out of the carburetor connection boot. 300900-10 – Remove screw – Remove the throttle slide cover and pull the throttle slide out of the carburetor. –...
31/CARBURETOR – Mount the carburetor connection boot. – Position and tighten hose clamp 300891-11 – Mount fuel hose – Check the play in the throttle cable. ( p. 20) – Carburetor - adjust the idle speed. ( p. 107) 300890-11 Installing the carburetor (50 SX Mini) 18.4...
31/CARBURETOR – Remove the plug. – Connect the oil line. 300897-10 – Tighten hose clip 300898-11 – Connect the fuel hose. – Bleed the oil pump. ( p. 117) – Check the play in the throttle cable. ( p. 20) –...
31/CARBURETOR – Check the jet needle. ( p. 106) – Check the throttle slide. ( p. 106) – Check the float needle valve. ( p. 106) – Check/set the float level. ( p. 107) – Check the choke slide. ( p.
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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 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 – Remove float and the float needle valve.
31/CARBURETOR – Remove screws – Remove the choke slide. 300920-10 – Note the setting of the idle air adjusting screw – Remove the idle air adjusting screw. 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...
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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 Mini) 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 1 turn Alternative 2 –...
31/CARBURETOR – Position the float chamber. – Mount and tighten screws Guideline Other screws, carburetor 2 Nm (1.5 lbf ft) 300917-11 – Mount the fuel hose on the carburetor. 300916-10 – Position the jet needle in the throttle slide. 300923-10 Checking the choke slide (50 SX) 18.11...
31/CARBURETOR » If the rubber sleeve is damaged or brittle, or if the lock is not functioning: – Change the choke slide. Checking the throttle slide (50 SX) 18.13 Condition The throttle slide has been removed. – Check the throttle slide for damage and wear. »...
31/CARBURETOR Checking/setting the float level (50 SX) 18.17 Condition The carburetor and float chamber have been removed. – Tilt the carburetor sideways, preventing the fulcrum pin from falling out. – Tilt the carburetor until the float is resting against the float needle valve, but the float needle valve is not being pressed together.
31/CARBURETOR Carburetor - adjusting idle speed (50 SX Mini) 18.19 – Screw in idle air adjusting screw all the way and turn it to the specified basic position. Guideline Idle air adjusting screw Open 1 turn – Run the engine until warm. Guideline ≥...
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. 300655-10 –...
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. –...
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32/CLUTCH Clutch spring with green mark – 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 1.2 mm (0.047 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. ( p. 113) 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.
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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. ( p. 115) 400721-01 – Fill up with gear oil. ( p. 115) 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. 138) – Mount and tighten screw cap. Danger Danger of poisoning Exhaust gases are poisonous and inhaling them may result in unconsciousness and/or death.
38/LUBRICATION SYSTEM Danger Danger of poisoning Exhaust gases are poisonous and inhaling them may result in unconsciousness and/or death. – When running the engine, always make sure there is sufficient ventila- tion, and do not start or run the engine in an enclosed space without an effective exhaust extraction system.
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38/LUBRICATION SYSTEM – Remove screws – Take off the oil pump. – Pull off the oil line from the carburetor. 300651-10 – Turn the oil pump gear anticlockwise until oil flows out of the oil line without ...
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. –...
TROUBLESHOOTING Faults Possible cause Action – Engine turns but does not start Operating error Go through the steps of starting the engine. p. 7) – Motorcycle was out of use for a long Empty the carburetor float chamber. time and there is old fuel in the float chamber –...
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TROUBLESHOOTING Faults Possible cause Action – Engine does not speed up Fault in ignition system Check the ignition system. ( p. 119) – Engine has too little power Fuel feed interrupted Check the fuel tank breather. – Clean the fuel tap. (50 SX Mini) –...
TECHNICAL DATA - CARBURETOR 50 SX 27.1 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 50 SX Mini 27.2 Carburetor type Dell`Orto PHVA 12XS...
TECHNICAL DATA - CHASSIS Capacity - fuel 28.2 Fuel tank capacity, approx. 2.3 l (2.4 qt.) Super unleaded gasoline, mixed with 2-stroke engine oil (1:60) (50 SX) p. 139) Fuel tank capacity, approx. 2.0 l (2.1 qt.) Super unleaded (ROZ 95 / RON 95 / PON 91) ( p.
TECHNICAL DATA - FORK 50 SX 29.1 Fork part number 45101000644 Fork Marzocchi Spring rate Weight of rider: 25… 35 kg (55… 77 lb.) 2 N/mm (11 lb/in) Air chamber length 100±2.5 mm (3.94±0.098 in) Fork length 692 mm (27.24 in) Fork oil 210 ml (7.1 fl.
TECHNICAL DATA - SHOCK ABSORBER 50 SX 30.1 Shock absorber part number 03.18.9E.02 Shock absorber WP Suspension 3614 BAEM Rebound damping Standard 10 clicks Spring preload Standard 3 mm (0.12 in) Spring rate Weight of rider: < 25 kg (< 55 lb.) 30 N/mm (171 lb/in) Weight of rider: 25…...
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. ( p. 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. ( p. 7) –...
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 Mini) ( p.
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SERVICE SCHEDULE S20A S40A S80A Check radial clearance of conrod bearing. • • • Change crankshafts and conrod bearings. • • Service the fork. ( p. 10) • • Service the shock absorber. ( p. 25) • Clean and lubricate swingarm bearing. •...
2-stroke engine oil According to – JASO FC ( p. 149) 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 –...
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SUBSTANCES Shock absorber oil (SAE 2.5) (50180342S1) According to – SAE ( p. 149) (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 –...
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SPECIAL TOOLS Bleed syringe Art. no.: 50329050000 400058-01 Holding spanner Art. no.: 54629012100 300676-01 Work stand Art. no.: 54829055000 500071-01 Peak voltage adapter Art. no.: 58429042000 400083-01 Torque wrench with various accessories in set Art. no.: 58429094000 200910-10...
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.