KTM 50 SX Mini 2012 Owner's manual

OWNER'S MANUAL 2012

50 SX

50 SX Mini

Art. no. 3211711en

DEAR KTM CUSTOMER 1

DEARKTM CUSTOMER

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

We wish you a lot of enjoyment in riding this vehicle.

Enter the serial numbers of your vehicle below.

Chassis number ( p. 9) Dealer's stamp

Engine number ( p. 9)

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

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

© 2011 KTM-Sportmotorcycle AG, Mattighofen Austria
All rights reserved
Reproduction, even in part, as well as copying of all kinds, is permitted only with the express written permission of the copyright
owner.

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

KTM-Sportmotorcycle AG
5230 Mattighofen, Austria

TABLE OF CONTENTS 2

TABLEOF CONTENTS

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

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

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

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

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

SERIAL NUMBERS.............................................................. 9

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

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

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

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

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

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

Kill switch .................................................................... 10

Opening filler cap.......................................................... 10

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

Opening oil tank cap (50 SX Mini) .................................. 11

Closing oil tank cap (50 SX Mini).................................... 11

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

Choke (50 SX)............................................................... 12

Choke (50 SX Mini) ....................................................... 12

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

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

Plug-in stand ................................................................ 12

PREPARING FOR USE ....................................................... 13

Advice on first use ......................................................... 13

Running in the engine.................................................... 14

RIDING INSTRUCTIONS .................................................... 15

Checks and maintenance measures when preparing for

use .............................................................................. 15

Starting ........................................................................ 15

Starting up ................................................................... 16

Riding .......................................................................... 16

Braking ........................................................................ 16

Stopping, parking .......................................................... 16

Refueling...................................................................... 17

Filling up with oil (50 SX Mini) ....................................... 17

SERVICE SCHEDULE......................................................... 18

Service schedule ........................................................... 18

TUNING THE CHASSIS...................................................... 20

Adjusting the rebound damping of the shock absorber....... 20

Measuring rear wheel sag unloaded ................................. 20

Checking the static sag of the shock absorber .................. 20

Checking the riding sag of the shock absorber .................. 21

Adjusting the spring preload of the shock absorber x ...... 21

Adjusting the riding sag x............................................. 22

Handlebar position ........................................................ 22

Adjusting handlebar position x...................................... 22

Adjusting seat height x ................................................ 23

MAINTENANCE WORK ON THE CHASSIS ........................... 24

Raising the motorcycle with a lift stand ........................... 24

Removing the motorcycle from the lift stand .................... 24

Cleaning the dust boots of the fork legs ........................... 24

Removing the fork legs x.............................................. 25

Installing the fork legs x............................................... 25

Removing the lower triple clamp x ................................ 26

Installing the lower triple clamp x................................. 26

Checking play of steering head bearing............................ 28

Adjusting the play of the steering head bearing x............ 28

Greasing the steering head bearing x............................. 29

Dismounting the start number plate ................................ 29

Installing the start number plate ..................................... 29

Dismounting the front fender .......................................... 29

Installing the front fender............................................... 30

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

Installing shock absorber x........................................... 30

Removing the seat ......................................................... 31

Mounting the seat ......................................................... 31

Removing the air filter x............................................... 31

Installing the air filter x ............................................... 32

Cleaning the air filter and air filter box x........................ 32

Removing main silencer ................................................. 32

Installing the main silencer ............................................ 33

Changing the glass fiber yarn filling of the main

silencer x ................................................................... 33

Removing the chain guard (50 SX).................................. 34

Installing the chain guard (50 SX)................................... 34

Removing the engine sprocket cover x ........................... 34

Installing the engine sprocket cover x............................ 34

Checking the chain for dirt ............................................. 35

Cleaning the chain......................................................... 35

Checking the chain tension ............................................ 35

Checking the chain, rear sprocket, engine sprocket and

chain guide................................................................... 36

Adjusting chain tension.................................................. 38

Adjusting the chain guide x.......................................... 38

Checking the frame x................................................... 38

Checking the swingarm x ............................................. 39

Checking the throttle cable routing.................................. 39

Checking the rubber grip ................................................ 39

Additionally securing the rubber grip ............................... 39

BRAKES........................................................................... 40

Checking the play of the hand brake lever ........................ 40

Adjusting the play of the hand brake lever........................ 40

Adjusting the basic position of the hand brake lever.......... 40

Checking brake discs ..................................................... 40

Checking front brake fluid level....................................... 41

Adding front brake fluid x ............................................ 41

Checking the front brake linings...................................... 42

Removing front brake linings x ..................................... 42

Installing the front brake linings x................................. 43

Changing the front brake linings x................................. 43

Checking the free travel of the foot brake lever ................. 44

Adjusting the free travel of the foot brake lever x............ 44

Adjusting the basic position of the foot brake lever x ...... 45

Checking rear brake fluid level ........................................ 45

Adding rear brake fluid x.............................................. 46

Checking the rear brake linings ....................................... 47

Removing rear brake linings x....................................... 47

Installing the rear brake linings x.................................. 47

Changing the rear brake linings x.................................. 48

WHEELS........................................................................... 50

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

Installing the front wheel x........................................... 50

Removing rear wheel x................................................. 51

Installing the rear wheel x ............................................ 51

Checking the tire condition............................................. 51

Checking tire air pressure ............................................... 52

Checking spoke tension.................................................. 52

COOLING SYSTEM ............................................................ 54

Cooling system .............................................................. 54

Checking the antifreeze and coolant level ........................ 54

Checking the coolant level.............................................. 55

TABLE OF CONTENTS 3

Draining the coolant x.................................................. 55

Refilling coolant x ....................................................... 56

TUNING THE ENGINE ....................................................... 57

Checking the play in the throttle cable............................. 57

Adjusting the play in the throttle cable x ....................... 57

Carburetor - idle (50 SX) ................................................ 57

Carburetor - idle (50 SX Mini)......................................... 57

Carburetor - adjusting idle speed x (50 SX).................... 57

Carburetor - adjusting idle speed x (50 SX Mini) ............ 58

Checking clutch engagement speed x............................ 59

Adjusting the clutch engagement speed x...................... 59

Removing the centrifugal force clutch x......................... 60

Installing the centrifugal force clutch x ......................... 61

Checking the centrifugal force clutch x.......................... 61

Dismantling centrifugal clutch x ................................... 62

Assembling centrifugal clutch x.................................... 62

MAINTENANCE WORK ON THE ENGINE............................. 64

Checking oil level (50 SX Mini)....................................... 64

Bleeding the oil pump x (50 SX Mini) ........................... 64

Checking the gear oil level.............................................. 65

Changing the gear oil x ................................................ 65

Draining the gear oil x ................................................. 66

Filling up with gear oil x .............................................. 66

Adding gear oil x ......................................................... 66

CLEANING........................................................................ 68

Cleaning motorcycle ...................................................... 68

STORAGE ......................................................................... 69

Storage......................................................................... 69

Preparing for use after storage ........................................ 69

TROUBLESHOOTING......................................................... 70

TECHNICAL DATA - ENGINE .............................................. 72

Capacity - gear oil.......................................................... 72

Capacity - coolant.......................................................... 72

TECHNICAL DATA - ENGINE TIGHTENING TORQUES .......... 73

TECHNICAL DATA - CARBURETOR..................................... 74

50 SX........................................................................... 74

50 SX Mini ................................................................... 74

TECHNICAL DATA - CHASSIS ............................................ 75

Tires ............................................................................ 75

Capacity - fuel............................................................... 76

TECHNICAL DATA - FORK.................................................. 77

50 SX........................................................................... 77

50 SX Mini ................................................................... 77

TECHNICAL DATA - SHOCK ABSORBER ............................. 78

50 SX........................................................................... 78

50 SX Mini ................................................................... 78

TECHNICAL DATA - CHASSIS TIGHTENING TORQUES ........ 79

SUBSTANCES................................................................... 80

AUXILIARY SUBSTANCES.................................................. 82

STANDARDS..................................................................... 84

INDEX .............................................................................. 85

MEANS OF REPRESENTATION 4

Symbols used

The symbols used are explained in the following.

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

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

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

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

Formats used

The typographical and other formats used are explained in the following.

Proper name Identifies a proper name.

®

Name

Brand™ Identifies a brand in merchandise traffic.

Identifies a protected name.

IMPORTANT INFORMATION 5

Use definition

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

Info

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

Service

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

Warranty

The work prescribed in the service schedule must be carried out in an authorized KTM workshop only and confirmed in the customer's
service record and in the KTM dealer.net 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.

Fuel, oils, etc.

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

Spare parts, accessories

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

The current KTM PowerParts for your vehicle can be found on the KTM website.
International KTM Website: http://www.ktm.com

Work rules

Special tools are needed for certain tasks. They are not included with the vehicle but can be ordered under the number in parenthe­ses. Ex.: bearing puller (15112017000)
During assembly, non-reusable parts (e.g. self-locking screws and nuts, seals, seal rings, O-rings, pins, lock washers) must be replaced
by new parts.
If a thread locker is used for the screw connections (e.g. Loctite®), follow the specific manufacturer instructions regarding its use.
Parts that are to be reused after disassembly must be cleaned and checked for damage and wear. Change damaged or worn parts.
After repair and maintenance, ensure that the vehicle is roadworthy.

Transport

Note

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

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

Note

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

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

being run. Always let the vehicle cool first.

– Switch off the engine.
– Use straps or other suitable devices to secure the motorcycle against accidents or falling over.

IMPORTANT INFORMATION 6

Environment

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

Notes/warnings

Pay close attention to the notes/warnings.

Info

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

Grades of risks

Danger

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

Warning

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

Caution

Identifies a danger that may lead to minor injuries if the appropriate measures are not taken.

Note

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

Warning

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

Owner's manual

– Carefully read this owner's manual in its entirety together with your child before letting your child ride the motorcycle for the first

time. It contains a lot of information and tips to help you and your child operate and handle the motorcycle. Only then will you
find out how to customize the motorcycle ideally for your child's use and how to protect your child from injury. The owner's manual
also contains important information on servicing the motorcycle.

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

sold.

VIEW OF VEHICLE 7

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

1 Filler cap
2 Quick release of seat
3 Fuel tap ( p. 11)
4 Choke ( p. 12)
5 Plug-in stand ( p. 12)
6 Chain guide

601573-10

VIEW OF VEHICLE 8

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

1 Kill switch ( p. 10)
2 Throttle grip ( p. 10)
3 Hand brake lever ( p. 10)
4 Chassis number ( p. 9)
5 Shock absorber rebound adjustment
6 Level viewer for brake fluid, rear
7 Foot brake lever ( p. 12)
8 Kickstarter ( p. 12)

601572-10

SERIAL NUMBERS 9

4.1Chassis number

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

601576-10

4.2Engine number

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

4.3Shock absorber part number

700461-01

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

700469-01

CONTROLS 10

5.1Throttle grip

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

601577-10

5.2Hand 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

5.3Kill switch

Kill switch  is fitted on the left side of the handlebar.

Possible states

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

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

601579-10

5.4Opening filler cap

Danger

Fire hazard Fuel is highly flammable.

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

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

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

Warning

Danger of poisoning Fuel is poisonous and a health hazard.

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

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

Warning

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

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

CONTROLS 11

– Turn the tank cap  counterclockwise and pull it up.

601580-10

5.5Closing filler cap

– Put the tank cap on and turn it clockwise.

Info

Run the fuel tank breather hose  without kinks.

601580-11

5.6Opening oil tank cap (50 SX Mini)

601582-10

5.7Closing oil tank cap (50 SX Mini)

601582-11

– Turn the oil tank cap  counterclockwise and pull it up.

– Put the oil tank cap on and turn it clockwise.

Info

Run the oil tank breather hose  without kinks.

5.8Fuel tap

Fuel tap  is on the left of the fuel tank.

Possible states

• Fuel tap is closed – The knurled screw is turned all the way clockwise. Fuel cannot
flow out of the fuel tank.

• Fuel tap is open – The knurled screw is turned all the way counterclockwise. Fuel
can flow out of the fuel tank.

601581-10

CONTROLS 12

5.9Choke (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 gives a richer fuel-air mixture, which is needed for a cold start.

Info

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

Possible states

• Choke function activated – Choke knob is in upper position. The O-ring is visible.

601583-10

5.10Choke (50 SX Mini)

700519-01

• Choke function deactivated – Choke knob is in lower position. No O-ring is visible.

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

Info

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

Possible states

• Choke function activated – The choke lever is pushed up all the way.

• Choke function deactivated – The choke lever is pushed down all the way.

5.11Kickstarter

5.12Foot brake lever

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

Info

Before riding, swing the kickstarter inwards towards the engine.

601584-10

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

601587-10

5.13Plug-in stand

The fixture for the plug-in stand  is located on the frame on the left side of the vehi­cle.
The plug-in stand is used to park the motorcycle.

Info

Remove the plug-in stand before riding.

601585-10

PREPARING FOR USE 13

6.1Advice on first use

Warning

Danger of accidents Physical and mental readiness of a child.

– Your child must be able to ride a bicycle and must be able to erect the vehicle independently after a fall. In addition, your

child must understand the regulations and instructions from you or from other guardians. Do not ask too much of your
child; participation in competitive activities should not be considered until your child's stamina, riding techniques and
motivation are at the necessary levels. Children often underestimate or fail to recognize dangerous situations; make it clear
to your child that it should not, under any circumstances, operate the vehicle without supervision and that your child may
only drive at speeds that are commensurate with the child's riding abilities and the road conditions.

– Only let your child ride on the vehicle if it is physically and mentally ready to operate the vehicle.

Warning

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

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

and your child should always used protective clothing that is in good condition and meets the legal requirements. When
you ride a motorcycle, set an example for your child and wear suitable protective clothing.

Warning

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

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

Warning

Danger of accidents Critical riding behavior due to inappropriate riding.

– Ensure that your child adjusts the riding speed to the road conditions and to his or her riding abilities.

Warning

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

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

Warning

Danger of accidents Brake system failure.

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

Ensure that your child raises his or her foot from the foot brake lever when the child does not want to brake.

Warning

Danger of accidents Destruction of chassis components.

– Do not exceed the maximum allowable rider weight.

Warning

Risk of misappropriation Usage by unauthorized persons.

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

Info

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

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

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

– Carefully read the entire owner's manual together with your child before going for the first ride.

Info

Pay special attention to the safety warnings and injury risks.
Explain to your child the techniques of riding and falling, e.g. how shifting weight can influence handling characteristics.

– Familiarize your child with the controls.
– Adjust the basic position of the hand brake lever. ( p. 40)

–

Adjust the basic position of the foot brake lever. x ( p. 45)

– Before using the vehicle for the first time, ensure that the basic settings of the chassis are suitable for the weight of your child.
– Accustom your child to the handling of the motorcycle on suitable terrain, preferably on a large open meadow.

PREPARING FOR USE 14

Info

To give your child a feel for the brake, you should push your child at first. Do not start the engine until your child is able to
apply the necessary brake pressure.
Initially, let your child drive to another person who can help your child stop and turn.

– Erect obstacles for your child to navigate around to accustom your child to handling the vehicle.
– Your child should also try to ride as slowly as possible and in a standing position to get a better feeling for the vehicle.
– Do not let your child ride on terrain that exceed your child's capabilities and experience.
– Your child should hold the handlebar firmly with both hands and keep his or her feet on the footrests when riding.
– Do not exceed the maximum allowable rider weight.

Guideline

Maximum rider weight < 35 kg (< 77 lb.)
Maximum rider size < 130 cm (< 51.2 in)

– Check the spoke tension. ( p. 52)

Info

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

– Run the engine in. ( p. 14)

6.2Running in the engine

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

Guideline

Maximum engine performance

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

– Avoid fully opening the throttle!

RIDING INSTRUCTIONS 15

7.1Checks 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. ( p. 65)

(50 SX Mini)

– Check the oil level. ( p. 64)
– Check the front brake brake fluid level. ( p. 41)
– Check the rear brake fluid level. ( p. 45)
– Check the front brake linings. ( p. 42)
– Check the rear brake linings. ( p. 47)
– Check that the brake system is functioning properly.
– Check the coolant level. ( p. 55)
– Check the chain dirt accumulation. ( p. 35)
– Check the chain, rear sprocket, engine sprocket, and chain guide. ( p. 36)
– Check the chain tension. ( p. 35)
– Check the tire condition. ( p. 51)
– Check the tire air pressure. ( p. 52)
– Check the spoke tension. ( p. 52)
– Clean the dust boots of the fork legs. ( p. 24)
– Check the air filter.
– Check the settings of all controls and ensure that they can be operated smoothly.
– Check all screws, nuts and hose clamps regularly for tightness.
– Check the fuel supply.

7.2Starting

Danger

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

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

space without an effective exhaust extraction system.

Note

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

– Always warm up the engine at low engine speeds.

Info

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

– Turn the knurled screw on the fuel tap all the way counterclockwise.

Fuel can flow from the fuel tank to the carburetor.

– Remove the motorcycle from the stand.

The engine is cold

(50 SX)

– Pull the choke knob fully out and turn it by max. ¼ turn.

(50 SX Mini)

– Push the choke lever up all the way.

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

Info

Do not open the throttle.

RIDING INSTRUCTIONS 16

7.3Starting up

Info

The plug-in stand must be removed before beginning to ride.

– Open the throttle carefully.

7.4Riding

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.
– When you reach maximum speed after fully opening the throttle, turn back the throttle to about ¾ of its range. The speed hardly

drops, but the fuel consumption falls considerably.
– Your child should always open the throttle only as much as the engine can handle – abruptly opening the throttle increases fuel

consumption.
– Your child should switch off the engine if he or she expects to be standing for a long time.

Guideline

≥ 2 min

7.5Braking

Warning

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

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

Warning

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

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

Warning

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

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

– On sandy, wet or slippery surfaces, use the rear brake.
– Braking should always be completed before you go into a bend.

7.6Stopping, parking

Warning

Risk of misappropriation Usage by unauthorized persons.

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

Warning

Danger of burns Some vehicle components become very hot when the vehicle is operated.

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

nents to cool down before starting work on them.

Note

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

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

Note

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

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

being run. Always let the vehicle cool first.

RIDING INSTRUCTIONS 17

00

0

AA

Note

Material damage Damage and destruction of components due to excessive load.

– The plug-in stand is designed for the weight of the motorcycle only. You or your child should not sit on the motorcycle when it is

standing on the plug-in stand. The plug-in stand and/or the frame could be damaged and the motorcycle could fall over.

– Brake the motorcycle.
– Press and hold the kill switch while the engine is idling until the engine stops.
– Turn the knurled screw on the fuel tap all the way clockwise.
– Park the motorcycle on firm ground.

7.7Refueling

Danger

Fire hazard Fuel is highly flammable.

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

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

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

Warning

Danger of poisoning Fuel is poisonous and a health hazard.

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

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

Warning

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

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

– Switch off the engine.
– Open the filler cap. ( p. 10)
– Fill the fuel tank with fuel up to measurement .

Guideline

Measurement of  35 mm (1.38 in)

400214-10

7.8Filling up with oil (50 SX Mini)

Fuel tank
capacity, approx.
(50 SX Mini)

Fuel tank
capacity, approx.
(50 SX)

– Close the filler cap. ( p. 11)

2.0 l (2.1 qt.) Super unleaded (ROZ 95/RON 95/PON

2.3 l (2.4 qt.) Super unleaded gasoline, mixed with

Warning

Engine failure If the vehicle is run without 2-stroke oil in the tank, the result is engine failure.

– The oil tank must always be filled up to the MIN mark.

91) ( p. 81)

2-stroke engine oil (1:60) ( p. 81)

601586-10

– Switch off the engine.
– Open the oil tank cap. ( p. 11)
– Fill the oil tank at least up to the MIN mark .

Guideline

MIN mark Sufficient for a single tank filling

Oil tank contents
ca.

– Close the oil tank cap. ( p. 11)

0.2 l (0.2 qt.) 2-stroke engine oil ( p. 80)

SERVICE SCHEDULE 18

8.1Service schedule

S10N S20A S40A S80A J1A

Change the gear oil. x ( p. 65)

Check the gear oil level. ( p. 65) • • •
Check the front brake linings. ( p. 42) • • • •
Check the rear brake linings. ( p. 47) • • • •
Check the brake discs. ( p. 40) • • • •
Check brake lines for damage and leakage. • • • •

Change the sealing sleeves of the foot brake cylinder. x
Change the rear brake fluid. x

Check the rear brake fluid level. ( p. 45) • • • •
Check the free travel of the foot brake lever. ( p. 44) • • • •

Check the frame and swingarm. x
Check swingarm bearing. x
Check the heim joints on the upper and lower shock absorbers. x
Service the fork. x
Service the shock absorber. x

Check the tire condition. ( p. 51) • • • •
Check the tire air pressure. ( p. 52) • • • •

Check wheel bearing for play. x
Check the wheel hub. x
Check rim run-out. x

Check the spoke tension. ( p. 52) • • • •
Check the chain, rear sprocket, engine sprocket, and chain guide. ( p. 36) • • • •
Check the chain tension. ( p. 35) • • • •
Lubricate all moving parts (e. g. hand levers, chain, ...) and check for smooth opera-

tion. x
Change the front brake fluid. x

Check the front brake brake fluid level. ( p. 41) • • • •
Check the play of the hand brake lever. ( p. 40) • • • •

Grease the steering head bearing. x ( p. 29)

Check play of steering head bearing. ( p. 28) • • • •

Change the piston. x
Change the connecting rod, conrod bearing and crank pin. x
Change the crankshaft bearing. x
Check the transmission. x
Change all engine bearings. x
Change the spark plug. x
Change the spark plug connector. x
Check the cylinder and piston. x
Check the intake membrane. x
Check the clutch. x

Check all hoses (e. g. fuel, cooling, bleeding, drainage) and sleeves for tearing, tight-

ness and correct routing. x

Check the antifreeze and coolant level. ( p. 54) • • • •

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

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

Clean the air filter and air filter box. x ( p. 32)
Change the glass fiber yarn filling of the main silencer. x ( p. 33)
Check the screws and nuts for tightness. x

• • •

• • •

•

• • •

• • •

• • •

• •

•

• • •

• • •

• • • •

• • • •

•

•

• •

• •

• •

• •

•

• • •

• •

• • •

• • •

• • •

• • • •

• • • •

• • • •

• • •

• • • •

SERVICE SCHEDULE 19

S10N S20A S40A S80A J1A

Check/set the carburetor components. x
Check idle. x
Check the clutch engagement speed. x ( p. 59)

Final inspection: check the vehicle for operating safety and take a test ride. • • • •

Create a service entry in the KTM DEALER.NET and in the service record. x

S10N: Once after 10 operating hours
S20A: Every 20 operating hours
S40A: Every 40 operating hours
S80A: Every 80 operating hours
J1A: Annually

• • • •

• • • •

• • • •

•

TUNING THE CHASSIS 20

00AA

00AA

0

0

BB

9.1Adjusting 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.
– 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 Mini)

601591-10

Standard 12 clicks

Info

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

9.2Measuring rear wheel sag unloaded

– Raise the motorcycle with a lift stand. ( p. 24)
– Measure the distance – as vertical as possible – between the rear axle and a fixed

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

– Make a note of the value as measurement .
– Remove the motorcycle from the lift stand. ( p. 24)

400988-10

9.3Checking the static sag of the shock absorber

– Measure distance  of rear wheel unloaded. ( p. 20)
– Hold the motorcycle in a vertical position with the assistance of another person.
– Measure the distance between the rear axle and the fixed point again.
– Make a note of the value as measurement .

– Check the static sag.

Info

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

Static sag (50 SX) 20 mm (0.79 in)

400989-10

Static sag (50 SX Mini) 15 mm (0.59 in)

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

–

Adjust the spring preload of the shock absorber. x ( p. 21)

TUNING THE CHASSIS 21

00AA

0

0

CC

9.4Checking the riding sag of the shock absorber

– Measure distance  of rear wheel unloaded. ( p. 20)
– With another person holding the motorcycle, the rider sits down on the saddle in

full protective clothing in a normal sitting position (feet on footrests) and bounces
up and down a few times.

The rear wheel suspension levels out.

– Another person now measures the distance between the rear axle and a fixed point.
– Make a note of the value as measurement .

Info

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

– Check the riding sag.

Riding sag (50 SX) 45… 55 mm (1.77… 2.17 in)

Riding sag (50 SX Mini) 40… 50 mm (1.57… 1.97 in)

» If the riding sag differs from the specified measurement:

–

Adjust the riding sag. x ( p. 22)

400990-10

9.5Adjusting the spring preload of the shock absorber x

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.)

–

Remove shock absorber. x ( p. 30)

– After removing the shock absorber, clean it thoroughly.
– Measure the full spring length while it is under tension and note down the value.
– Loosen retaining ring .
– Turn adjusting ring  until the spring is no longer under tension.

Hook wrench (T106S)

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

Guideline

700506-01

Spring preload (50 SX)

Standard 3 mm (0.12 in)

Spring preload (50 SX Mini)

Standard 5 mm (0.2 in)

Info

The spring preload is the difference between the relaxed spring length and
the tensioned spring length.
Depending on the static sag and/or the riding sag, it may be necessary to
increase or decrease the spring preload.

– Tighten retaining ring .

–

Install shock absorber. x ( p. 30)

TUNING THE CHASSIS 22

000BB

0

0

AA

0011

0

0

22

9.6Adjusting the riding sag x

–

Remove shock absorber. x ( p. 30)

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

Guideline

Spring rate (50 SX)

B00292-10

Weight of rider: 15… 25 kg (33…
55 lb.)

Weight of rider (standard): 25…
35 kg (55… 77 lb.)

Weight of rider: 35… 45 kg (77…
99 lb.)

Spring rate (50 SX Mini)

Weight of rider: 15… 25 kg (33…
55 lb.)

Weight of rider (standard): 25…
35 kg (55… 77 lb.)

Weight of rider: 35… 45 kg (77…
99 lb.)

30 N/mm (171 lb/in)

35 N/mm (200 lb/in)

40 N/mm (228 lb/in)

65 N/mm (371 lb/in)

75 N/mm (428 lb/in)

85 N/mm (485 lb/in)

Info

The spring rate is shown on the outside of the spring.
Smaller weight differences can be compensated by changing the spring
preload.

–

Install shock absorber. x ( p. 30)

– Check the static sag of the shock absorber. ( p. 20)
– Check the riding sag of the shock absorber. ( p. 21)
– Adjust the rebound damping of the shock absorber. ( p. 20)

9.7Handlebar position

On the upper triple clamp, there are 2 holes at a distance of  to each other.

Distance  between holes 15 mm (0.59 in)

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

Distance  between holes 3.5 mm (0.138 in)

The handlebar supports can be mounted in 4 different positions.

400565-10

9.8Adjusting handlebar position x

Warning

Danger of accidents Handlebar breakage.

– If the handlebar is bent or straightened it will cause material fatigue, and the handlebar can break. Always replace handle-

bar.

400564-10

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

and lay it to one side.

Info

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

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

screws .

TUNING THE CHASSIS 23

Guideline

Screw, handlebar support M10 40 Nm

(29.5 lbf ft)

– Position the handlebar.

Info

Make sure cables and wiring are positioned correctly.

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

Guideline

Screw, handlebar clamp M8 20 Nm

Info

Make sure the gap width is even.

9.9Adjusting seat height x

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.

Loctite®243™

(14.8 lbf ft)

601589-10

– Raise the motorcycle with a lift stand. ( p. 24)
– Hold the rear wheel with the swingarm and remove screw .
– Position the shock absorber according to the required seat height.

Guideline

Low seat position (standard) 
High seat position 

– Mount and tighten screw .

Guideline

Screw, top shock absorber M10 45 Nm

(33.2 lbf ft)

– Remove the motorcycle from the lift stand. ( p. 24)

MAINTENANCE WORK ON THE CHASSIS 24

10.1Raising 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 (59229055000)

The tires should no longer be in contact with the ground.

– Secure the motorcycle against falling over.

601590-01

10.2Removing the motorcycle from the lift stand

Note

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

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

601585-10

10.3Cleaning the dust boots of the fork legs

601592-10

– Remove the motorcycle from the lift stand.
– Remove the lift stand.
– To park the motorcycle, insert plug-in stand  into the plug-in stand bracket on

the left side of the vehicle.

Info

Remove the plug-in stand before riding.

– Raise the motorcycle with a lift stand. ( p. 24)
– Push dust boots  of both fork legs downwards.

Info

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

Warning

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

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

brake cleaner when necessary.

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

Universal oil spray ( p. 83)

– Press the dust boots back into their normal position.
– Remove excess oil.
– Remove the motorcycle from the lift stand. ( p. 24)

MAINTENANCE WORK ON THE CHASSIS 25

10.4Removing the fork legs x

–

Remove the front wheel. x ( p. 50)

– Remove screws  and take off the clamp.
– Remove screws  and take off the brake caliper.
– Hang the brake caliper and the brake line loosely to the side.

601593-10

– Loosen screw . Remove the left fork leg.
– Loosen screw . Remove the right fork leg.

601594-10

10.5Installing the fork legs x

601595-10

601594-11

– 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.
Position bleeder screws  to the front.

– Tighten screws .

Guideline

Screw, top triple clamp M8 20 Nm

– Tighten screws .

Guideline

Screw, bottom triple clamp M8 15 Nm

– Position brake caliper, mount, and tighten screws .

Guideline

Screw, front brake caliper M8 20 Nm

(14.8 lbf ft)

(14.8 lbf ft)

(11.1 lbf ft)

Loctite®243™

601593-11

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

–

Install the front wheel. x ( p. 50)