KTM 50 SX 2019 Owner's Manual
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KTM 50 SX 2019 Owner's Manual

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OWNER'S MANUAL
2019
50 SX
50 SX Mini
Art. no. 3213844en

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Summary of Contents for KTM 50 SX 2019

  • Page 1 OWNER'S MANUAL 2019 50 SX 50 SX Mini Art. no. 3213844en...
  • Page 3 DEAR KTM CUSTOMER Congratulations on your decision to purchase a KTM motorcycle. You are now the owner of a state-of-the-art DEAR KTM CUSTOMER sports motorcycle that will give you and your child enormous pleasure if you service and maintain it accordingly.

  • Page 4: Table Of Contents

    TABLE OF CONTENTS Running in the engine ...... 22 TABLE OF CONTENTS MEANS OF REPRESENTATION ...... 5 RIDING INSTRUCTIONS......23 Symbols used ........5 Formats used........5 Checks and maintenance measures when preparing for use ..... 23 SAFETY ADVICE..........6 Starting the vehicle ......
  • Page 5 TABLE OF CONTENTS 11.2 Removing the motorcycle from the 12.2 Adjusting the play of the hand brake lift stand ......... 42 lever ..........70 11.3 Bleeding the fork legs....... 42 12.3 Adjusting the basic position of the hand brake lever ......70 11.4 Cleaning the dust boots of the fork legs ..........
  • Page 6 TABLE OF CONTENTS 16.2 Bleeding the oil pump (50 SX Mini) ......... 100 16.3 Checking the gear oil level ....101 16.4 Changing the gear oil ....102 16.5 Adding gear oil ......103 17 CARBURETOR .......... 105 17.1 Removing the carburetor (50 SX Mini) .........

  • Page 7: Means Of Representation 1

    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 work- shop. There, your motorcycle will be optimally cared for by specially trained experts using the specialist tools required.

  • Page 8: Safety Advice

    2 SAFETY ADVICE Use definition – intended use This vehicle is designed and built to withstand the normal stresses and strains of competitive use. This vehicle complies with the currently valid regulations and categories of the top international motorsports organizations. Info Only operate this vehicle in closed-off areas remote from public road traffic.

  • Page 9: Tampering Warning

    Only operate the vehicle when it is in perfect technical condition, in accordance with its intended use and in a safe and environmentally compatible manner. The vehicle should only be used by trained persons. Have malfunctions that impair safety promptly eliminated by an authorized KTM workshop. Adhere to the information and warning labels on the vehicle.

  • Page 10: Protective Clothing

    – When you ride a motorcycle, set an example for your child and wear suitable protective clothing. In the interest of your own safety, KTM recommends that you only operate the vehicle while wearing suitable pro- tective clothing. Work rules Special tools are necessary for certain tasks.
  • Page 11 SAFETY ADVICE 2 The Owner's Manual is also available for download from your authorized KTM dealer and on the KTM website. International KTM Website: http://www.ktm.com...

  • Page 12: Important Notes

    Manufacturer and implied warranty The work specified in the service schedule may only be performed in an authorized KTM workshop and must be recorded in both the Service & Warranty Booklet and in the KTM Dealer.net, otherwise any warranty coverage will become void.
  • Page 13 IMPORTANT NOTES 3 A list of authorized KTM dealers can be found on the KTM website. International KTM Website: http://www.ktm.com...

  • Page 14: View Of Vehicle

    4 VIEW OF VEHICLE View of vehicle, front left (example) K01117-10 Filler cap Quick release of seat Chain guide Plug-in stand ( p. 19) Choke Fuel tap ( p. 18)

  • Page 15: View Of Vehicle, Rear Right (Example)

    VIEW OF VEHICLE 4 View of vehicle, rear right (example) K01118-10 Kill switch ( p. 16) Throttle grip ( p. 16) Hand brake lever ( p. 16) Vehicle identification number ( p. 14) Kick starter ( p. 19) Foot brake lever ( p.

  • Page 16: Serial Numbers

    5 SERIAL NUMBERS Vehicle identification number The vehicle identification number is stamped on the right side of the steering head. 401945-10 Type label (50 SX) The type label is located on the front frame tube. 402154-10 (50 SX Mini) Type label is fixed to the front of the steering head.

  • Page 17: Fork Part Number

    SERIAL NUMBERS 5 Fork part number The fork part number is stamped on the outside of the axle clamp. 401947-10 Shock absorber article number (50 SX) The shock absorber article number is stamped on the bot- tom of the shock absorber toward the right-hand side. H01186-10 (50 SX Mini) The shock absorber article number...

  • Page 18: Controls

    6 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. K01119-11 Throttle grip Throttle grip is fitted on the right side of the handlebar. K01119-10 Kill switch Kill switch...

  • Page 19: Closing The Fuel Tank Filler Cap

    CONTROLS 6 Warning Danger of poisoning Fuel is poisonous and a health hazard. – Avoid skin, eye and clothing contact with fuel. – Immediately consult a doctor if you swallow fuel. – Do not inhale fuel vapors. – In case of skin contact, rinse the affected area with plenty of water. –...

  • Page 20: Closing Oil Tank Cap (50 Sx Mini)

    6 CONTROLS Closing oil tank cap (50 SX Mini) – Put the oil tank cap on and turn it clockwise. Info Run the oil tank breather hose without kinks. V00253-11 Fuel tap Fuel tap is on the left of the fuel tank. Possible states Fuel tap is closed –...

  • Page 21: Kick Starter

    CONTROLS 6 Possible states Choke function activated – The choke lever is pushed up all • the way to the stop. Choke function deactivated – The choke lever is pushed down • all the way to the stop. 6.11 Kick starter Kick starter is fitted on the right side of the engine.

  • Page 22: Preparing For Use

    7 PREPARING FOR USE Advice on preparing for first use Warning Danger of accidents A lack of physical and mental readiness on the part of the child poses a major risk. Children often underestimate or fail to recognize dangerous situations. – Your child must already be able to ride a bicycle.
  • Page 23 When using the motorcycle, remember that others may feel disturbed by excessive noise. – Ensure that the pre-delivery inspection work has been carried out by an authorized KTM workshop. The delivery certificate and the Service and Manufacturer Warranty Booklet must be transferred with the vehicle.

  • Page 24: Running In The Engine

    7 PREPARING FOR USE – Run the engine in. ( p. 22) Running in the engine – During the running-in phase, do not exceed the specified engine performance. Guideline Maximum engine performance During the first 3 operating hours < 70 % During the first 5 operating hours <...

  • Page 25: Riding Instructions 8

    RIDING INSTRUCTIONS 8 Checks and maintenance measures when preparing for use Info Before every trip, check the condition of the vehicle and ensure that it is safe to operate. The vehicle must be in perfect technical condition when it is being operated. –...

  • Page 26: Starting Off

    Open the throttle carefully. Riding Info If unusual noises occur while riding, stop immediately, switch off the engine and contact an authorized KTM workshop. – If the choke function has been activated, deactivate it after the engine has warmed up. –...

  • Page 27: Applying The Brakes

    Danger of accidents A spongy pressure point on the front or rear brake reduces braking efficiency. – Check the brake system and do not allow your child to continue riding until the problem is eliminated. (Your authorized KTM workshop will be glad to help.) Warning Danger of accidents Moisture and dirt impair the brake system.

  • Page 28: Transporting

    8 RIDING INSTRUCTIONS Transporting Note Danger of damage The parked vehicle can roll away or fall over. – Park the vehicle on a firm and level surface. Note Fire hazard Hot vehicle components pose a fire hazard and explosion risk. – Do not park the vehicle near to materials which are highly flammable or explosive. –...

  • Page 29: Filling Up With Oil (50 Sx Mini)

    RIDING INSTRUCTIONS 8 – Fill the fuel tank with fuel up to measurement 0 0 0 Guideline 35 mm (1.38 in) Measurement of Fuel tank capacity, 2.1 l (2.2 qt.) Super unleaded approx. (50 SX Mini) (ROZ 95/RON 95/PON 91) p.

  • Page 30: Service Schedule

    Different service intervals may apply in your country, depending on the local operating conditions. Individual service intervals and scopes may change in the course of technical developments. The most up-to-date service schedule can always be found on KTM Dealer.net. Your authorized KTM dealer will be happy to advise you.

  • Page 31: Recommended Work

    ● Final check: Check the vehicle for safe operation and take a test ride. ○ ● ● ● Make the service entry in KTM Dealer.net and in the Service & Manufacturer Warranty Book- let. ○ One-time interval ● Periodic interval...

  • Page 32: 10 Tuning The Chassis

    – As delivered, KTM offroad motorcycles are adjusted for an average rider's weight (with full protective clothing). Guideline Standard rider weight 25 …...

  • Page 33: Compression Damping Of The Shock Absorber (50 Sx)

    The shock absorber is filled with highly compressed nitrogen. – Please follow the description provided. (Your authorized KTM workshop will be glad to help.) Info The effect of the low-speed setting can be seen in slow to normal compression of the shock absorber.

  • Page 34: Adjusting The High-Speed Compression Damping Of The Shock Absorber (50 Sx)

    The shock absorber is filled with highly compressed nitrogen. – Please follow the description provided. (Your authorized KTM workshop will be glad to help.) Info The effect of the high-speed setting can be seen in fast compression of the shock absorber.
  • Page 35 TUNING THE CHASSIS 10 Guideline Rebound damping Comfort 17 clicks Standard 15 clicks Sport 13 clicks Info Turn clockwise to increase damping; turn counter- clockwise to reduce damping. (50 SX Mini) – Raise the motorcycle with a lift stand. ( p.

  • Page 36: Measuring The Rear Wheel Dimension Unloaded

    10 TUNING THE CHASSIS – Position the shock absorber and rear wheel. – Mount and tighten screw and nut Guideline Screw, bottom 45 Nm (33.2 lbf ft) Loctite ® 243™ shock absorber – Remove the motorcycle from the lift stand. ( p.

  • Page 37: Checking The Riding Sag Of The Shock Absorber

    Risk of injury Parts of the shock absorber will move around if the shock absorber is detached incorrectly. The shock absorber is filled with highly compressed nitrogen. – Please follow the description provided. (Your authorized KTM workshop will be glad to help.) Preparatory work (50 SX) –...
  • Page 38 10 TUNING THE CHASSIS – Tighten the spring by turning adjusting ring to the specified measurement. Guideline Spring preload Standard 3 mm (0.12 in) Info The spring preload is the difference between the relaxed spring length and the tensioned spring length.

  • Page 39: Adjusting The Riding Sag

    TUNING THE CHASSIS 10 10.11 Adjusting the riding sag Preparatory work (50 SX) – Raise the motorcycle with a lift stand. ( p. 42) (50 SX Mini) – Raise the motorcycle with a lift stand. ( p. 42) – Remove the rear wheel. p.

  • Page 40: Checking The Basic Setting Of The Fork

    10 TUNING THE CHASSIS 10.12 Checking the basic setting of the fork Info For various reasons, no exact riding sag can be determined for the fork. (50 SX) – Smaller differences in the rider's weight can be compen- sated for by the fork air pressure. –...

  • Page 41: Adjusting The Rebound Damping Of The Fork (50 Sx)

    TUNING THE CHASSIS 10 Info This is due to the volume of the hose and not due to a defect in the fork airpump or the fork. Read the accompanying KTM PowerParts instructions. – Adjust the air pressure as specified. Guideline...

  • Page 42: Handlebar Position

    10 TUNING THE CHASSIS 10.15 Handlebar position On the upper triple clamp, there are 2 holes at a distance of each other. 15 mm (0.59 in) Hole distance The holes on the handlebar support are placed at a distance of 0 0 A from the center.

  • Page 43: Adjusting The Seat Height

    TUNING THE CHASSIS 10 10.17 Adjusting the seat height Warning Danger of accidents Modifications to the suspension setting may seriously alter the handling characteris- tic. – Ride slowly to start with after making adjustments to get the feel of the new handling characteristic. Preparatory work –...

  • Page 44: 11 Service Work On The Chassis

    11 SERVICE WORK ON THE CHASSIS 11.1 Raising the motorcycle with a lift stand Note Danger of damage The parked vehicle can roll away or fall over. – Park the vehicle on a firm and level surface. – Raise the motorcycle at the frame underneath the engine. Lift stand (78929955100) Neither wheel is in contact with the ground.

  • Page 45: Cleaning The Dust Boots Of The Fork Legs

    SERVICE WORK ON THE CHASSIS 11 (50 SX Mini) – Release bleeder screws Any excess pressure escapes from the interior of the fork. – Tighten the bleeder screws. H01183-11 Finishing work – Remove the motorcycle from the lift stand. ( p.

  • Page 46: Removing The Fork Protector

    11 SERVICE WORK ON THE CHASSIS 11.5 Removing the fork protector – Remove screws and take off the clamp. – Remove screws on the left fork leg. Take off the fork pro- tector. V00266-10 – Remove screws on the right fork leg. Take off the fork pro- tector.

  • Page 47: Removing The Fork Legs

    SERVICE WORK ON THE CHASSIS 11 11.7 Removing the fork legs Preparatory work – Raise the motorcycle with a lift stand. ( p. 42) – Remove the front wheel. p. 84) Main work – Remove screws and take off the clamp. –...
  • Page 48 11 SERVICE WORK ON THE CHASSIS – Tighten screws Guideline Screw, top triple 20 Nm clamp (14.8 lbf ft) – Tighten screws Guideline Screw, bottom 15 Nm triple clamp (11.1 lbf ft) V00269-11 (50 SX Mini) – Position the fork legs. Bleeder screws are positioned toward the front.

  • Page 49: Removing The Lower Triple Clamp

    SERVICE WORK ON THE CHASSIS 11 11.9 Removing the lower triple clamp Preparatory work – Raise the motorcycle with a lift stand. ( p. 42) – Remove the front wheel. p. 84) – Remove the fork legs. p. 45) – Remove the start number plate.
  • Page 50 11 SERVICE WORK ON THE CHASSIS – Position the upper triple clamp with the handlebar. – Mount nut , but do not tighten it yet. V00282-10 (50 SX) – Position the fork legs. Bleeder screws are positioned toward the front. Info The second milled groove (from the top) must be flush with the upper edge of the upper triple clamp.
  • Page 51 SERVICE WORK ON THE CHASSIS 11 (50 SX Mini) – Position the fork legs. Bleeder screws are positioned toward the front. Info The second milled groove (from the top) must be flush with the upper edge of the upper triple clamp. H01183-10 –...

  • Page 52: Checking The Steering Head Bearing Play

    Danger of accidents Incorrect steering head bearing play impairs the handling characteristic and dam- ages components. – Correct incorrect steering head bearing play immediately. (Your authorized KTM workshop will be glad to help.) Info If the vehicle is operated for a lengthy period with play in the steering head bearing, the bearings and the bearing seats in the frame can become damaged over time.

  • Page 53: Adjusting The Steering Head Bearing Play

    SERVICE WORK ON THE CHASSIS 11 11.12 Adjusting the steering head bearing play Preparatory work – Raise the motorcycle with a lift stand. ( p. 42) Main work (50 SX) – Pull fuel tank breather out of the steering stem. –...

  • Page 54: Greasing The Steering Head Bearing

    11 SERVICE WORK ON THE CHASSIS – Tighten screws Guideline Screw, top triple 20 Nm clamp (14.8 lbf ft) – Position fuel tank breather in the steering stem. Finishing work – Check the steering head bearing play. ( p. 50) –...

  • Page 55: Installing The Fuel Tank

    SERVICE WORK ON THE CHASSIS 11 Main work – Remove screw R00530-10 – Raise the fuel tank. – Pull off fuel hose Info Remaining fuel may flow out of the fuel hose. – Pull fuel tank breather out of the steering stem. –...

  • Page 56: Removing The Start Number Plate

    11 SERVICE WORK ON THE CHASSIS – Mount fuel hose R00531-11 – Position the fuel tank. – Make sure that no cables or throttle cables are trapped or dam- aged. – Mount and tighten screw Guideline Remaining screws, 10 Nm (7.4 lbf ft) chassis –...

  • Page 57: Removing Front Fender

    SERVICE WORK ON THE CHASSIS 11 – Mount and tighten screw Guideline Screw, start number 4 Nm (3 lbf ft) plate H01427-10 11.18 Removing front fender – Remove screws . Take off the front fender. H01428-10 11.19 Installing front fender –...

  • Page 58: Removing The Shock Absorber

    11 SERVICE WORK ON THE CHASSIS 11.20 Removing the shock absorber Preparatory work (50 SX) – Raise the motorcycle with a lift stand. ( p. 42) (50 SX Mini) – Raise the motorcycle with a lift stand. ( p. 42) –...

  • Page 59: Installing The Shock Absorber

    SERVICE WORK ON THE CHASSIS 11 11.21 Installing the shock absorber Warning Danger of accidents Modifications to the suspension setting may seriously alter the handling characteris- tic. – Ride slowly to start with after making adjustments to get the feel of the new handling characteristic. Main work (50 SX) –...

  • Page 60: Removing The Seat

    11 SERVICE WORK ON THE CHASSIS 11.22 Removing the seat – Open quick release and raise the rear of the seat. – Pull back the seat and remove it. H00066-10 11.23 Mounting the seat – Hook the seat onto screw , lower the seat at the rear, and push it forward.

  • Page 61: Installing The Air Filter

    SERVICE WORK ON THE CHASSIS 11 Main work – Press rear holding lug together slightly and swing the air filter box cover upward. – Pull out the front holding lug and take off the air filter box cover. – Take off the air filter. H01432-10 11.25 Installing the air filter...

  • Page 62: Removing The Main Silencer

    11 SERVICE WORK ON THE CHASSIS Finishing work – Install the air filter. p. 59) – Mount the seat. ( p. 58) 11.27 Removing the main silencer Warning Danger of burns The exhaust system gets very hot when the vehicle is driven. –...

  • Page 63: Removing The Engine Sprocket Cover

    SERVICE WORK ON THE CHASSIS 11 Main work – Remove screws with toothed washers from the silencer – Remove end cap and outer tube – Remove glass fiber yarn filling from the inner tube. – Clean the parts that need to be reinstalled and check for dam- age.

  • Page 64: Installing The Engine Sprocket Cover

    11 SERVICE WORK ON THE CHASSIS 11.31 Installing the engine sprocket cover Main work (50 SX) – Position the engine sprocket cover. Mount screws do not tighten yet. – Mount and tighten screw Guideline Screw, engine 12 Nm (8.9 lbf ft) sprocket cover H01437-10 –...

  • Page 65: Cleaning The Chain

    SERVICE WORK ON THE CHASSIS 11 11.33 Cleaning the chain Warning Danger of accidents Lubricants on the tires reduces the road grip. – Remove lubricants from the tires using a suitable cleaning agent. Warning Danger of accidents Oil or grease on the brake discs reduces the braking effect. –...

  • Page 66: Adjusting The Chain Tension

    11 SERVICE WORK ON THE CHASSIS Main work (50 SX) – Press the chain upward at the end of the chain sliding piece and determine chain tension Info The upper part of the chain must be taut. Chain wear is not always even, so you should repeat this measurement at different chain positions.

  • Page 67: Checking The Chain, Rear Sprocket, Engine Sprocket And Chain Guide

    SERVICE WORK ON THE CHASSIS 11 Main work – Loosen nut – Adjust the chain tension by turning adjusting nuts left and right. Guideline Chain tension 5 … 8 mm (0.2 … 0.31 in) Turn adjusting nuts equally on the left and right. The rear wheel must be aligned with the front wheel.
  • Page 68 11 SERVICE WORK ON THE CHASSIS – Check the chain sliding guard for wear. » If the ridge is worn down to the level of the main corpus: – Change the chain sliding guard. – Check that the chain sliding guard is firmly seated. »...

  • Page 69: Adjusting The Chain Guide

    If the frame exhibits cracks or deformation due to a mechanical impact: – Change the frame. Info Always replace a frame that has been dam- aged due to a mechanical impact. Repair of the frame is not authorized by KTM. S00876-01...

  • Page 70: Checking The Link Fork

    – Change the link fork. Info Always replace a damaged link fork. Repairing the link fork is not authorized by KTM. S00877-01 11.40 Checking the throttle cable routing Warning Danger of accidents The throttle cable may slip out of the guide if routed incorrectly.

  • Page 71: Additionally Securing The Rubber Grip

    SERVICE WORK ON THE CHASSIS 11 11.42 Additionally securing the rubber grip Preparatory work – Check the rubber grip. ( p. 68) Main work – Secure the rubber grip at two locations with the retaining wire. Securing wire (54812016000) Wire twister forceps (U6907854) The twisted wire ends face away from the palms and are bent in toward the rubber grip.

  • Page 72: 12 Brake System

    12 BRAKE SYSTEM 12.1 Checking play of handbrake lever Warning Danger of accidents The brake system fails in the event of overheating. If there is no free travel on the hand brake lever, pressure builds up on the front brake circuit. –...

  • Page 73: Checking The Brake Discs

    Warning Danger of accidents Worn-out brake discs reduce the braking effect. – Make sure that worn-out brake discs are replaced immediately. (Your authorized KTM workshop will be glad to help.) – Check the front and rear brake disc thickness at multiple...

  • Page 74: Checking The Front Brake Fluid Level

    Danger of accidents Old brake fluid reduces the braking effect. – Make sure that brake fluid for the front and rear brake is changed in accordance with the service schedule. (Your authorized KTM workshop will be glad to help.) Note Environmental hazard Hazardous substances cause environmental damage.

  • Page 75: Adding The Front Brake Fluid

    Danger of accidents Old brake fluid reduces the braking effect. – Make sure that brake fluid for the front and rear brake is changed in accordance with the service schedule. (Your authorized KTM workshop will be glad to help.) Note Environmental hazard Hazardous substances cause environmental damage.

  • Page 76: Checking The Front Brake Linings

    Checking the front brake linings Warning Danger of accidents Worn-out brake linings reduce the braking effect. – Ensure that worn-out brake linings are replaced immediately. (Your authorized KTM workshop will be glad to help.) – Check the brake linings for minimum thickness ≥...
  • Page 77 Danger of accidents Brake linings which have not been approved alter the braking efficiency. Not all brake linings are tested and approved for KTM motorcycles. The structure and friction coefficient of the brake linings, and thus their brake power, may vary greatly from that of original brake linings.
  • Page 78 12 BRAKE SYSTEM – Remove screw – Press back the brake linings by slightly tilting the brake caliper laterally on the brake disc. Carefully pull the brake caliper backward from the brake disc. – Press the brake piston back into the basic position and ensure that brake fluid does not flow out of the brake fluid reservoir;...

  • Page 79: Checking The Free Travel Of The Foot Brake Lever

    BRAKE SYSTEM 12 Guideline Screw, front M8x60 20 Nm (14.8 lbf ft) Loctite ® 243™ brake caliper – Tighten screw Guideline Screw, front M8x40 20 Nm (14.8 lbf ft) Loctite ® 243™ brake caliper – Remove the locking piece of the hand brake lever. –...

  • Page 80: Adjusting The Free Travel Of The Foot Brake Lever

    12 BRAKE SYSTEM 12.10 Adjusting the free travel of the foot brake lever Warning Danger of accidents The brake system fails in the event of overheating. If there is no free travel on the foot brake lever, pressure builds up in the brake system on the rear brake.

  • Page 81: Checking The Rear Brake Fluid Level

    Danger of accidents Old brake fluid reduces the braking effect. – Make sure that brake fluid for the front and rear brake is changed in accordance with the service schedule. (Your authorized KTM workshop will be glad to help.) – Stand the vehicle upright.
  • Page 82 Danger of accidents Old brake fluid reduces the braking effect. – Make sure that brake fluid for the front and rear brake is changed in accordance with the service schedule. (Your authorized KTM workshop will be glad to help.) Note Environmental hazard Hazardous substances cause environmental damage.

  • Page 83: Checking The Rear Brake Linings

    Checking the rear brake linings Warning Danger of accidents Worn-out brake linings reduce the braking effect. – Ensure that worn-out brake linings are replaced immediately. (Your authorized KTM workshop will be glad to help.) – Check the brake linings for minimum thickness ≥...
  • Page 84 Danger of accidents Brake linings which have not been approved alter the braking efficiency. Not all brake linings are tested and approved for KTM motorcycles. The structure and friction coefficient of the brake linings, and thus their brake power, may vary greatly from that of original brake linings.
  • Page 85 BRAKE SYSTEM 12 – Remove screws – Take off cover with washer and membrane – Press the brake piston back into the basic position and ensure that brake fluid does not flow out of the brake fluid reservoir; extract some if necessary. H01448-11 –...

  • Page 86: 13 Wheels, Tires

    13 WHEELS, TIRES 13.1 Removing the front wheel Preparatory work – Raise the motorcycle with a lift stand. ( p. 42) Main work – Remove screw – Loosen screws H01451-10 Warning Danger of accidents Damaged brake discs reduce the braking effect. –...

  • Page 87: Removing The Rear Wheel

    WHEELS, TIRES 13 – Check the wheel bearing for damage and wear. » If the wheel bearing is damaged or worn: – Change front wheel bearing. – Clean and grease the contact surfaces of the spacers. Long-life grease ( p. 127) –...

  • Page 88: Installing The Rear Wheel

    13 WHEELS, TIRES Warning Danger of accidents Damaged brake discs reduce the braking effect. – Always lay the wheel down in such a way that the brake disc is not damaged. – Take the rear wheel out of the link fork. Info Do not operate the foot brake lever when the rear wheel is removed.

  • Page 89: Checking The Tire Condition

    DOT number. The first two digits indicate the week of manufacture and the last two digits the year of manu- facture. KTM recommends that the tires be changed after 5 H01144-10 years at the latest, regardless of the actual state of wear.

  • Page 90: Checking Tire Pressure

    Other spokes will become looser as a result. – Check spoke tension regularly, and in particular on a new vehicle. (Your authorized KTM workshop will be glad to help.) –...

  • Page 91: Cooling System 14

    COOLING SYSTEM 14 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.

  • Page 92: Checking The Coolant Level

    14 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 open the radiator, the radiator hoses or other cooling system components if the engine or the cooling system are at operating temperature.

  • Page 93: Refilling With Coolant

    COOLING SYSTEM 14 Warning Danger of poisoning Coolant is toxic and a health hazard. – Keep coolant out of the reach of children. – Do not allow coolant to come into contact with the skin, the eyes and clothing. – Consult a doctor immediately if coolant is swallowed. –...
  • Page 94 14 COOLING SYSTEM – Move the vehicle into the position shown and prevent it from rolling away. Height difference must be reached. Guideline 50 cm (19.7 in) Height difference Info 0 0 A 0 0 B For all of the air to be able to escape from the cooling system, the vehicle must be raised at the front.

  • Page 95: Tuning The Engine 15

    TUNING THE ENGINE 15 15.1 Checking the installation position of the throttle grip Warning Danger of accidents The throttle cable may slip out of the guide if the throttle grip installation position is incorrect. The throttle slide will then no longer be closed and the speed can no longer be controlled. –...

  • Page 96: Adjusting The Throttle Cable Play

    15 TUNING THE ENGINE 15.3 Adjusting the throttle cable play Preparatory work – Check the installation position of the throttle grip. ( p. 93) – Remove the seat. ( p. 58) – Turn the knurled screw on the fuel tap all the way clockwise. –...

  • Page 97: Carburetor - Idle (50 Sx Mini)

    TUNING THE ENGINE 15 15.5 Carburetor - idle (50 SX Mini) The idle setting of the carburetor has a big influence on the start- ing behavior, stable idling, and the response to throttle opening. This means that an engine with a correctly set idle speed is easier to start than if the idle speed is set wrongly.

  • Page 98: Carburetor - Adjusting The Idle Speed (50 Sx Mini)

    15 TUNING THE ENGINE Info If there is a big engine speed rise, reduce the idle speed to a normal level and repeat the above steps. If the procedure described here does not lead to sat- isfactory results, the cause may be a wrongly dimen- sioned idling jet.

  • Page 99: Checking The Clutch Setting

    TUNING THE ENGINE 15 Info If there is a big engine speed rise, reduce the idle speed to a normal level and repeat the above steps. If the procedure described here does not lead to sat- isfactory results, the cause may be a wrongly dimen- sioned idling jet.

  • Page 100: Removing The Clutch Cover

    15 TUNING THE ENGINE 15.9 Removing the clutch cover Note Environmental hazard Improper handling of fuel is a danger to the environment. – Do not allow fuel to enter the groundwater, the soil, or the sewage system. Info Fuel can emerge via the carburetor. Capture emerging fuel using a suitable container.

  • Page 101: Installing The Clutch Cover

    TUNING THE ENGINE 15 Condition If there is no reference point: – Turn adjusting screws counterclockwise to the last detectable click. – Turn adjusting screws clockwise by 9 clicks to the basic setting. Guideline Basic setting of slip speed 8,700 … 9,300 rpm H01479-10 Info The springs may not be pretensioned by more than...

  • Page 102: 16 Service Work On The Engine

    16 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 toMIN mark at a minimum.

  • Page 103: Checking The Gear Oil Level

    SERVICE WORK ON THE ENGINE 16 – Remove screws – Take off the oil pump. – Pull off oil line from the carburetor. 300651-10 – Turn oil pump gear wheel counterclockwise until oil flows out of oil line without bubbles. V00276-10 –...

  • Page 104: Changing The Gear Oil

    16 SERVICE WORK ON THE ENGINE (50 SX Mini) – Remove screw – Check the gear oil level. A small quantity of gear oil must run out of the drilled hole. » If no gear oil runs out: – Add gear oil. p.

  • Page 105: Adding Gear Oil

    SERVICE WORK ON THE ENGINE 16 (50 SX Mini) – Place an appropriate container under the engine. – Remove oil drain plug with the magnet. – Let the gear oil drain fully. – Thoroughly clean the oil drain plug with magnet. –...
  • Page 106 16 SERVICE WORK ON THE ENGINE Main work (50 SX) – Remove screw for checking gear oil level H00083-10 (50 SX Mini) – Remove screw for checking gear oil level S00882-10 – Remove filler plug with the O-ring. – Add gear oil until it flows out of the hole of the gear oil level plug.

  • Page 107: Carburetor 17

    CARBURETOR 17 17.1 Removing the carburetor (50 SX Mini) Danger Fire hazard Fuel is highly flammable. The fuel in the fuel tank expands when warm and can escape if overfilled. – Do not refuel the vehicle in the vicinity of open flames or lit cigarettes. –...

  • Page 108: Removing The Carburetor (50 Sx)

    17 CARBURETOR – Loosen hose clip – Loosen hose clip – Pull the carburetor out of the intake flange. – Pull the carburetor forward out of the inlet sleeve. T00392-10 – Remove screw – Take off the throttle slide cover and pull the throttle slide out of the carburetor.
  • Page 109 CARBURETOR 17 Preparatory work – Turn the knurled screw on the fuel tap all the way clockwise. Main work – Pull off fuel hose Info Remaining fuel may flow out of the fuel hose. R00564-10 – Loosen hose clip – Loosen hose clip R04489-10 –...

  • Page 110: Installing The Carburetor (50 Sx Mini)

    17 CARBURETOR 17.3 Installing the carburetor (50 SX Mini) Main work – Attach throttle cable wire 300903-10 – Position spring retainer – Position the throttle slide spring. 300902-11 – Position the throttle slide and throttle slide cover. – Mount and tighten screw Guideline Screw, throttle slide 3 Nm (2.2 lbf ft)

  • Page 111: Installing The Carburetor (50 Sx)

    CARBURETOR 17 – Connect fuel hose T00390-11 Finishing work – Bleed the oil pump. p. 100) – Check the throttle cable play. ( p. 93) – Carburetor – adjust the idle speed. p. 96) 17.4 Installing the carburetor (50 SX) Main work –...
  • Page 112 17 CARBURETOR – Mount the carburetor. – Mount the engine breather hose and position clamp R00566-11 – Mount the inlet sleeve. – Position and tighten hose clip – Position and tighten hose clip R04489-11 – Mount fuel hose R00564-11 Finishing work –...

  • Page 113: Cleaning, Care 18

    CLEANING, CARE 18 18.1 Cleaning the motorcycle Note Material damage Components become damaged or destroyed if a pressure cleaner is used incorrectly. The high pressure forces water into the electrical components, connectors, throttle cables, and bearings, etc. Pressure which is too high causes malfunctions and destroys components. –...
  • Page 114 18 CLEANING, CARE Info The heat produced causes water at inaccessible loca- tions in the engine and on the brake system to evapo- rate. – Push back the protection caps on the handlebar controls to allow water to evaporate. – After the motorcycle has cooled off, lubricate all moving parts and pivot points.

  • Page 115: Storage 19

    88) – Store the vehicle in a dry location that is not subject to large fluctuations in temperature. Info KTM recommends jacking up the motorcycle. – Raise the motorcycle with a lift stand. ( p. 42) – Cover the vehicle with a tarp or similar cover that is permeable to air.

  • Page 116: Preparing For Use After Storage

    19 STORAGE 19.2 Preparing for use after storage – Remove the motorcycle from the lift stand. ( p. 42) – Perform checks and maintenance measures when preparing for use. ( p. 23) – Take a test ride. 401059-01...

  • Page 117: Troubleshooting 20

    TROUBLESHOOTING 20 Faults Possible cause Action – Engine turns but does not start Operating error Carry out the start procedure. p. 23) – Motorcycle was out of use for a Empty the carburetor float chamber. long time and there is old fuel in the float chamber –...
  • Page 118 20 TROUBLESHOOTING Faults Possible cause Action Engine does not speed up The carburetor is flowing over (50 SX) – Check/set the carburetor compo- because the float needle is nents. dirty or worn (50 SX Mini) – Check/set the carburetor compo- nents.
  • Page 119 TROUBLESHOOTING 20 Faults Possible cause Action – Engine overheats Bent radiator hose Change the radiator hose. – White smoke emission (steam Damaged cylinder head or Check the cylinder head or cylinder in exhaust gas) cylinder head gasket head gasket. – Gear oil exits at the vent hose Too much gear oil added Check the gear oil level.

  • Page 120: 21 Technical Data

    21 TECHNICAL DATA 21.1 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...

  • Page 121: Carburetor With Carburetor Tuning

    TECHNICAL DATA 21 Screw, intake flange 5 Nm (3.7 lbf ft) Loctite ® 243™ Screw, pressure plate 10 Nm (7.4 lbf ft) Loctite ® 243™ Screw, water pump cover 10 Nm (7.4 lbf ft) Screw, cylinder head 18 Nm (13.3 lbf ft) Nuts, cylinder base 20 Nm (14.8 lbf ft) Screw, outer clutch hub...

  • Page 122: Capacities

    21 TECHNICAL DATA 21.4 Capacities 21.4.1 Gear oil Gear oil 0.20 l (0.21 qt.) Gear oil (ATF Dexron 3) ( p. 126) 21.4.2 Coolant Coolant 0.7 l (0.7 qt.) Coolant ( p. 125) 21.4.3 Fuel Fuel tank capacity, approx. 2.3 l (2.4 qt.) Super unleaded (95 octane) mixed (50 SX) with 2-stroke engine oil (1:60)

  • Page 123: Tires

    2.75 - 10 38J TT Maxxis MAXX CROSS SI Maxxis MAXX CROSS SI The tires specified represent one of the possible series production tires. Additional information is available in the Service section under: http://www.ktm.com 21.7 Fork 21.7.1 50 SX Fork part number 07.18.6Q.02...

  • Page 124: Shock Absorber

    21 TECHNICAL DATA Weight of rider (standard): 25 … 35 kg (55 … 2.0 N/mm (11.4 lb/in) 77 lb.) Weight of rider: 35 … 45 kg (77 … 99 lb.) 2.2 N/mm (12.6 lb/in) Spring length with preload spacer(s) 337.5 mm (13.287 in) Fork oil per fork leg 240 ±...

  • Page 125: Chassis Tightening Torques

    TECHNICAL DATA 21 Standard 5 mm (0.2 in) Spring rate Weight of rider: 15 … 25 kg (33 … 55 lb.) 65 N/mm (371 lb/in) Weight of rider (standard): 25 … 35 kg (55 … 75 N/mm (428 lb/in) 77 lb.) Weight of rider: 35 …...
  • Page 126 21 TECHNICAL DATA Screw, rear sprocket 25 Nm (18.4 lbf ft) Loctite ® 243™ Screw, steering stem 20 Nm (14.8 lbf ft) Screw, top triple clamp 20 Nm (14.8 lbf ft) Nut, link fork pivot 45 Nm (33.2 lbf ft) Remaining nuts, chassis 45 Nm (33.2 lbf ft) Remaining screws, chassis...

  • Page 127: Substances 22

    SUBSTANCES 22 Brake fluid DOT 4 / DOT 5.1 Standard/classification – Guideline – Use only brake fluid that complies with the specified standard (see specifications on the container) and that exhibits the corresponding properties. Recommended supplier Castrol – REACT PERFORMANCE DOT 4 MOTOREX ®...
  • Page 128 22 SUBSTANCES Gear oil (ATF Dexron 3) Standard/classification – Dexron III (ATF Dexron 3) Guideline – Use only ATF gear oils that comply with the specified standards (see specifications on the container) and that possess the necessary properties. Recommended supplier MOTOREX ®...

  • Page 129: Auxiliary Substances 23

    AUXILIARY SUBSTANCES 23 Air filter cleaner Recommended supplier MOTOREX ® – Racing Bio Dirt Remover Chain cleaner Recommended supplier MOTOREX ® – Chain Clean Fuel additive Recommended supplier MOTOREX ® – Fuel Stabilizer High viscosity grease Recommended supplier ® – LGHB 2 Long-life grease Recommended supplier...
  • Page 130 Preserving materials for paints, metal and rubber Recommended supplier MOTOREX ® – Moto Protect Rubber grip adhesive (00062030051) Recommended supplier KTM AG – GRIP GLUE Special cleaner for glossy and matte paint finishes, metal and plastic surfaces Recommended supplier MOTOREX ® –...

  • Page 131: Standards 24

    STANDARDS 24 JASO FD JASO FD 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 viscosity.

  • Page 132: 25 List Of Abbreviations

    25 LIST OF ABBREVIATIONS Art. no. Article number circa compare e.g. for example etc. et cetera i.a. inter alia number poss. possibly...

  • Page 133: Index

    INDEX Choke ......18 INDEX Cleaning ......111-112 Accessories .
  • Page 134 INDEX Front fender removing ......60 installing ......55 Manufacturer warranty .
  • Page 135 INDEX Service ......10 Service hour counter ..... 19 Vehicle identification number .
  • Page 136 *3213844en* 3213844en 11/2018 KTM Sportmotorcycle GmbH 5230 Mattighofen/Austria Photo: Mitterbauer/KTM http://www.ktm.com...

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50 sx mini 20193213844en 2019

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