KTM 125 SX 2022 (01) PDF DOCUMENT

The meaning of specific symbols is described below.

This vehicle has been designed and built to withstand the normal stresses and strains of racing. This vehicle complies with the currently valid regulations and categories of the top international motorsports organizations.

Only operate this vehicle in closed-off areas remote from public road traffic.

This vehicle has been designed and built to withstand the normal stresses and strains of racing. This vehicle complies with the currently valid regulations and categories of the top international motorsports organizations.

Only operate this vehicle in closed-off areas remote from public road traffic.

This vehicle is designed for use in offroad endurance competition, and not primarily for use in motocross.

The vehicle must only be used as intended. Dangers can arise for people, property and the environment through use not as intended. Any use of the vehicle beyond the intended and defined use constitutes misuse. Misuse also includes the use of operating and auxiliary fluids which do not meet the required specification for the respective use.

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.

Note (Environmental)

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

Tampering with the noise control system is prohibited. Federal law prohibits the following acts or the causing thereof:

1. The removal or rendering inoperative by any person other than for purposes of servicing, repair, or replacement, of any device or element of design incorporated into any new vehicle for the purpose of noise control prior to its sale or delivery to the ultimate purchaser or while it is in use, or

2. the use of the vehicle after such device or element of design has been removed or rendered inoperative by any person.

Among those acts presumed to constitute tampering are the acts listed below:

1. Removal or puncturing of the main silencers, baffles, header pipes or any other components which conduct exhaust gases.

2. Removal or puncturing of parts of the intake system.

3. Lack of proper maintenance.

4. Replacing moving parts of the vehicle, or parts of the exhaust system or intake system, with parts other than those specified by the manufacturer.

Danger of accidents: A rider who is not fit to ride poses a danger to him or herself and others.

– Do not operate the vehicle if you are not fit to ride due to alcohol, drugs or medication.

– Do not operate the vehicle if you are physically or mentally impaired.

Danger of poisoning: Exhaust gases are toxic and inhaling them may result in unconsciousness and death.

– Always make sure there is sufficient ventilation when running the engine.

– Use effective exhaust extraction when starting or running the engine in an enclosed space.

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

– Do not touch any parts such as the exhaust system, radiator, engine, shock absorber, or brake system before the vehicle parts have cooled down.

– Let the vehicle parts cool down before you perform any work on the vehicle.

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.

Warning – Risk of injury: Missing or poor protective clothing presents an increased safety risk.

– Wear appropriate protective clothing such as helmet, boots, gloves as well as trousers and a jacket with protectors on all rides.

– Always wear protective clothing that is in good condition and meets the legal regulations.

Unless specified otherwise, the ignition must be turned off during all work (models with ignition lock, models with remote key) or the engine must be at a standstill (models without ignition lock or remote key).

Special tools are necessary for certain tasks. The tools are not a component of the vehicle, but can be ordered using the number in parentheses.

During assembly, use new parts to replace parts which cannot be reused (e.g. self-locking screws and nuts, expansion screws, seals, sealing rings, O-rings, pins, and lock washers).

In the case of certain screws, a screw adhesive (e.g. Loctite®) is required. Observe the manufacturer’s instructions.

If thread locker (e.g., Precote®) has already been applied to a new part, do not apply any additional thread locker.

After disassembly, clean the parts that are to be reused and check them for damage and wear. Change damaged or worn parts.

After completing a repair or service work, check the operating safety of the vehicle.

If you use your motorcycle responsibly, you can ensure that problems and conflicts do not occur. To protect the future of the motorcycle sport, make sure that you use your motorcycle legally, display environmental consciousness, and respect the rights of others.

When disposing of used oil, other operating and auxiliary fluids, and used components, comply with the laws and regulations of the respective country.

Read the owner’s manual carefully and completely before making your first trip. The Owner’s Manual contains useful information and many tips on how to operate, handle, and service your motorcycle. This is the only way to find out how best to customize the vehicle for your own use and how you can protect yourself from injury.

Vehicle Identification Number (VIN): Stamped on the right side of the steering head.

Type Label: Fixed to the front of the steering head.

Engine Number: Stamped on the left side of the engine under the engine sprocket.

Fork Part Number: Stamped on the inside of the axle clamp.

Shock Absorber Article Number: Stamped on the top of the shock absorber above the adjusting ring towards the engine side.

Clutch lever: Fitted on the handlebar on the left. The clutch is activated hydraulically and adjusts itself automatically.

Hand brake lever: Fitted on the right side of the handlebar. Engages the front brake.

Throttle grip: Fitted on the right side of the handlebar.

Stop button: Fitted on the left side of the handlebar. In the basic position, the ignition circuit is closed and the engine can be started. When pressed, the ignition circuit is interrupted, stopping a running engine or preventing a non-running engine from starting.

Start button (125 XC US): Fitted on the right side of the handlebar. When pressed, the starter motor is actuated.

Fuel tank filler cap: On top of the fuel tank. To open, turn counterclockwise (All SX models) or press the release button and turn counterclockwise (125 XC US).

Fuel tap (All SX models): On the left side of the fuel tank. Positions are OFF (fuel supply closed) and ON (fuel supply open).

Fuel tap (125 XC US): On the left side of the fuel tank. Positions are OFF (fuel supply closed), ON (fuel supply to reserve level), and RES (reserve fuel supply).

Choke: Fitted on the left side of the carburetor. Pull out to activate for a cold start, push in to deactivate.

Shift lever: Mounted on the left of the engine. Gear positions are shown in a diagram, with neutral between first and second gears.

Kick starter lever: Fitted on the right side of the engine. It can be swiveled.

Foot brake lever: Located in front of the right footrest. Activates the rear brake.

Plug-in stand (All SX models): The holder is the left side of the wheel spindle. Used to park the motorcycle.

Side stand (125 XC US): Located on the left of the vehicle. Used for parking. Must be folded up and secured with a rubber strap when riding.

Service hour counter: Fitted in front of the handlebar. Shows the total number of service hours of the engine.

– Ensure that the pre-sales inspection work has been carried out by an authorized KTM workshop.

– Before riding for the first time, read the entire Owner’s Manual carefully.

– Get to know the controls.

– Adjust the basic position of the clutch lever.

– Adjust the basic position of the hand brake lever.

– Adjust the basic position of the foot brake lever.

– Adjust the basic position of the shift lever.

– Get used to the handling characteristics of the motorcycle on a suitable surface before undertaking more challenging trips.

– Try to ride as slowly as possible and in a standing position to get a better feel for the motorcycle.

– Do not make any off-road trips that exceed your ability and experience.

– Hold the handlebar firmly with both hands and keep your feet on the footrests when riding.

– Do not take luggage along.

– Do not exceed the maximum permissible weight and axle loads.

Guideline

– Check the spoke tension. The spoke tension must be checked after half an hour of operation.

– Run in the engine.

During the running-in phase, do not exceed the specified engine performance. Avoid fully opening the throttle.

Guideline – Maximum engine performance

Use of the vehicle under difficult conditions, such as on sand or on wet and muddy surfaces, can result in significantly increased wear. It may be necessary to inspect or replace parts before the next scheduled service.

– Prepare air filter box cover for securing.

– Clean the air filter and air filter box. Check the air filter approx. every 30 minutes.

– Check the electrical connector for humidity and corrosion and to ensure it is firmly seated. If found, clean and dry the connector, or change it if necessary.

– Make sure that no radiator covers are installed.

Difficult operating conditions include:

– Rides on dry sand.

– Rides on wet sand.

– Rides on wet and muddy circuits.

– Riding at high temperatures or slow riding.

– Riding at low temperatures and in snow.

– Check the radiator cap. The value on the cap should be 1.8 bar (26 psi). If it doesn’t match, change the cap.

– Mount the air filter dust cover (79006920000).

– Mount the air filter sand cover (79006922000).

– Adjust the carburetor jetting and setting. Your authorized KTM workshop can recommend the right tuning.

– Clean the chain.

– Mount the steel sprocket.

– Grease the chain.

– Clean the radiator fins and straighten any bent fins.

Condition for regular use in sand: Change the piston every 10 operating hours.

– Check the radiator cap. The value should be 1.8 bar (26 psi). If it doesn’t match, change it.

– Mount the air filter rain cover (79006921000 for wet sand, 79006921000 for wet/muddy circuits).

– Adjust the carburetor jetting and setting. An authorized workshop can recommend the correct tuning.

– Clean the chain (for wet sand).

– Mount the steel sprocket.

– Grease the chain (for wet sand).

– Clean the radiator fins and straighten any bent fins.

– Clean the motorcycle (for wet/muddy circuits).

Condition for regular use in sand: Change the piston every 10 operating hours.

– Check the radiator cap. The value should be 1.8 bar (26 psi). If it doesn’t match, change it.

– Adjust the secondary drive to the road conditions. The engine oil heats up quickly when the clutch is operated frequently due to an excessively high secondary ratio.

– Clean the chain.

– Clean the radiator fins and straighten any bent fins.

– Check the coolant level.

– Mount the air filter rain cover (79006921000).

– Adjust the carburetor jetting and setting. An authorized workshop can recommend the correct tuning.

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.

– Check the gear oil level.

– Check the front brake fluid level.

– Check the rear brake fluid level.

– Check the front brake linings.

– Check the brake linings of the rear brake.

– Check that the brake system is functioning properly.

– Check the coolant level.

– Check the chain for dirt.

– Check the chain, rear sprocket, engine sprocket, and chain guide.

– Check the chain tension.

– Check the tire condition.

– Check tire pressure.

– Check the spoke tension. (Spoke tension must be checked regularly).

– Clean the dust boots of the fork legs.

– Bleed the fork legs.

– 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 level.

Note: High revving speed with a cold engine negatively impacts the lifespan of the engine. Always run the engine warm at a low speed.

If the motorcycle has been out of use for more than 1 week, empty the carburetor float chamber first.

For All SX models:

1. Turn the tap handle of the fuel tap to the ON position.

2. Remove the plug-in stand.

3. Shift the transmission into neutral.

4. If the engine is cold, pull the choke lever out as far as possible.

5. Press the kick starter lever robustly through its full range. Do not open the throttle.

For 125 XC US model:

1. Turn the tap handle of the fuel tap to the ON position.

2. Take the motorcycle off the side stand and secure it with the rubber strap.

3. Shift the transmission into neutral.

4. If the engine is cold, pull the choke lever out as far as possible.

5. Press the start button or press the kick starter lever forcefully all the way. Do not open the throttle.

Ensure the plug-in stand is removed (SX models) or the side stand is folded up and secured (XC model) before riding.

Pull the clutch lever, shift into first gear, release the clutch lever slowly and at the same time open the throttle carefully.

– Shift into a higher gear when conditions allow. Release the throttle, pull the clutch lever, shift, release the clutch lever, and open the throttle.

– If the choke was activated, deactivate it after the engine has warmed up.

– After reaching maximum speed, turn the throttle back to ¾ open. This barely reduces speed but significantly lowers fuel consumption.

– Only open the throttle as much as the engine can handle. Abrupt opening increases fuel consumption.

– To shift down, apply the brakes and close the throttle at the same time. Pull the clutch lever, shift to a lower gear, release the clutch lever slowly, and either open the throttle or shift again.

– Switch off the engine if running at idle or stationary for a long time (≥ 2 min).

– Avoid frequent or lengthy slipping of the clutch. This causes the gear oil, engine, and cooling system to heat up.

– Ride at a low engine speed instead of a high engine speed with a slipping clutch.

Warning: Do not change into a low gear at high engine speed, as the rear wheel can block and the engine can race.

Warning: Excessively forceful application of the brakes blocks the wheels. Adjust application of the brakes to the respective riding situation and surface conditions.

Warning: A spongy pressure point on the front or rear brake reduces braking efficiency. Check the brake system and do not continue riding until the problem is eliminated.

Warning: Moisture and dirt impair the brake system. Brake carefully several times to dry out and remove dirt from the brake linings and brake discs.

– On sandy, wet, or slippery surfaces, use the rear brake mostly if possible.

– Always finish braking before you go into a bend. Change down to a lower gear appropriate to your road speed.

– Use the braking effect of the engine on long downhill stretches. Change down one or two gears, but do not over-rev the engine. This reduces the need to apply the brakes and prevents the brake system from overheating.

1. Apply the brakes on the motorcycle.

2. Shift the transmission to neutral position.

3. Press and hold the stop button while the engine is idling until the engine stops.

4. Park the vehicle on a firm and level surface.

For All SX models:

– Turn the tap handle of the fuel tap to the OFF position.

– Rest the vehicle on the plug-in stand.

For 125 XC US:

– Turn the tap handle of the fuel tap to the OFF position.

– Rest the vehicle on the side stand.

– Park the vehicle on a firm and level surface.

– Allow the vehicle to cool down before covering it to avoid fire hazards.

For All SX models:

– Switch off the engine.

– Mount the plug-in stand on the fork legs. The brake line should run in front of the stand and not get wedged.

– Use tension belts or other suitable devices to secure the motorcycle against falling over or rolling away. Tighten belts only to the point that the stand is firmly in contact with the fender and tires.

For 125 XC US:

– Switch off the engine.

– Use tension belts or other suitable devices to secure the motorcycle against falling over or rolling away.

Danger – Fire hazard: Fuel is highly flammable.

– Do not fuel near open flames or lit cigarettes.

– Switch off the engine for refueling.

– Avoid spilling fuel, especially on hot parts. Wipe up spills immediately.

Procedure:

1. Switch off the engine.

2. Open the fuel tank filler cap.

3. Fill the fuel tank with fuel up to measurement A.

4. Close the fuel tank filler cap.

● = Periodic interval, ○ = One-time interval

● = Periodic interval, ○ = One-time interval

For optimal riding characteristics, the basic settings of the suspension components must match the rider’s weight. First adjust the shock absorber, then the fork.

As delivered, the motorcycle is adjusted for a standard rider weight (with full protective clothing).

Guideline

If your weight is above or below this range, the basic setting must be adjusted accordingly.

Small weight differences can be compensated by adjusting the spring preload. For large weight differences, the springs must be replaced.

The effect of the low-speed compression adjuster is seen in slow to normal compression of the shock absorber.

1. Turn adjusting screw ① clockwise with a screwdriver as far as the last perceptible click. Do not loosen fitting ②.

2. Turn counterclockwise by the number of clicks corresponding to the shock absorber type.

Guideline – Lowspeed compression damping (All SX models / 125 XC US)

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

The effect of the high-speed compression adjuster is seen in fast compression of the shock absorber.

1. Turn adjusting screw ① all the way clockwise with a socket wrench. Do not loosen fitting ②.

2. Turn counterclockwise by the number of turns corresponding to the shock absorber type.

Guideline – Highspeed compression damping (All SX models)

Guideline – Highspeed compression damping (125 XC US)

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

1. Turn adjusting screw ① clockwise up to the last perceptible click.

2. Turn counterclockwise by the number of clicks corresponding to the shock absorber type.

Guideline – Rebound damping (All SX models)

Guideline – Rebound damping (125 XC US)

Turn clockwise to increase the damping; turn counterclockwise to reduce damping when the shock absorber rebounds.

Measuring Rear Wheel Dimension Unloaded (Dimension A)

1. Raise the motorcycle with a lift stand so the rear wheel is off the ground.

2. Position a sag gage in the rear axle and measure the distance to the “SAG” marking on the rear fender.

3. Note down this value as dimension A.

4. Remove the motorcycle from the lift stand.

Checking the Static Sag

1. Measure dimension A as described above.

2. Hold the motorcycle upright with the help of an assistant.

3. Measure the distance again between the rear axle and the “SAG” marking using the sag gage. Note this value as dimension B.

4. The static sag is the difference between A and B. Compare it to the guideline.

5. If the static sag is incorrect, adjust the spring preload of the shock absorber.

Checking the Riding Sag

1. Measure dimension A as described above.

2. With an assistant holding the motorcycle, the rider (in full protective gear) sits on the seat in a normal position (feet on footrests) and bounces up and down a few times.

3. The assistant measures the distance again between the rear axle and the “SAG” marking. Note this value as dimension C.

4. The riding sag is the difference between A and C. Compare it to the guideline.

5. If the riding sag is incorrect, adjust it by changing the shock absorber spring.

Adjusting Spring Preload

1. Raise the motorcycle with a lift stand and remove the shock absorber.

2. Clean the shock absorber thoroughly.

3. Loosen screw ①.

4. Turn adjusting ring ② until the spring is no longer under tension. Use a hook wrench (90129051000).

5. Measure the total spring length while not under tension.

6. Tension the spring by turning adjusting ring ② to the specified dimension A.

7. Tighten screw ① to 5 Nm (3.7 lbf ft).

8. Install the shock absorber and remove the bike from the lift stand.

Adjusting Riding Sag

1. Raise the motorcycle, remove the shock absorber, and clean it.

2. Choose and mount a suitable spring based on rider weight. The spring rate is shown on the outside of the spring.

3. Install the shock absorber.

4. Remove the bike from the lift stand.

5. Check the static sag and riding sag again.

6. Adjust the rebound damping of the shock absorber.

Warning: Modifications to the suspension setting may seriously alter the handling characteristic. Only make adjustments within the recommended range.

1. Raise the motorcycle with a lift stand.

2. Remove protection cap ① from the left fork leg.

3. Push together fork airpump ② fully and connect it to the left fork leg. The indicator will switch on automatically.

4. Adjust the air pressure as specified.

5. Disconnect the fork airpump. Excess pressure will escape from the hose, not the fork leg.

6. Mount the protection cap by hand.

7. Remove the motorcycle from the lift stand.

The hydraulic compression damping determines the fork suspension behavior. The adjusting screw ① is at the upper end of the right fork leg.

1. Turn adjusting screw ① clockwise all the way.

2. Turn counterclockwise by the number of clicks corresponding to the fork type.

Guideline – Compression damping (All SX models / 125 XC US)

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

The hydraulic rebound damping determines the fork suspension behavior. The adjusting screw ① is at the lower end of the right fork leg.

1. Turn adjusting screw ① clockwise all the way.

2. Turn counterclockwise by the number of clicks corresponding to the fork type.

Guideline – Rebound damping (All SX models)

Guideline – Rebound damping (125 XC US)

Turn clockwise to increase damping; turn counterclockwise to reduce damping when the shock absorber rebounds.

Warning: A repaired handlebar poses a safety risk. If the handlebar is bent or straightened, change it.

1. Remove the handlebar cushion.

2. Remove screws ① and the handlebar clamp. Lay the handlebar to one side, covering components to protect them.

3. Remove screws ② and take off handlebar supports ③.

4. Position rubber bushings ④ and push through nuts ⑤ from below.

5. Place the handlebar supports in the required position (the supports are longer on one side for two position options).

6. Mount and tighten screws ② to 40 Nm (29.5 lbf ft) using Loctite®243™.

7. Position the handlebar, ensuring cables are positioned correctly.

8. Position the handlebar clamp. Mount screws ① but do not tighten yet.

9. First, bolt the handlebar clamp with screws ① onto the longer, higher side of the handlebar supports so both parts touch. Tighten to 20 Nm (14.8 lbf ft).

10. Tighten the other side of screws ① evenly to 20 Nm (14.8 lbf ft).

11. Mount the handlebar cushion.

1. Park the vehicle on a firm and level surface.

2. Ensure that nobody sits on the vehicle when it is parked on a stand.

3. Raise the motorcycle at the frame underneath the engine using a lift stand (78129955100).

4. Ensure neither wheel is in contact with the ground.

5. Secure the motorcycle against falling over.

For All SX models:

1. Remove the motorcycle from the lift stand.

2. Remove the lift stand.

3. To park the motorcycle, insert plug-in stand ① into the left side of the wheel spindle. Remove the plug-in stand before riding.

For 125 XC US:

1. Remove the motorcycle from the lift stand.

2. Remove the lift stand.

3. To park, press side stand ① to the ground with your foot and lean the motorcycle on it. When riding, the side stand must be folded up and secured with the rubber strap.

1. Raise the motorcycle with a lift stand.

2. Release bleeder screws ①. Any excess pressure escapes from the interior of the fork.

3. Tighten the bleeder screws.

4. Remove the motorcycle from the lift stand.

1. Raise the motorcycle with a lift stand.

2. Remove the fork protector.

3. Push dust boots ① of both fork legs downward.

4. Clean and oil the dust boots and inner fork tubes of both fork legs using Universal oil spray.

5. Press the dust boots back into their normal position.

6. Remove excess oil.

7. Install the fork protector.

8. Remove the motorcycle from the lift stand.

Removing the fork legs:

1. Raise the motorcycle and remove the front wheel.

2. Remove screws ① and take off the clamp.

3. Remove screws ② and take off the brake caliper, letting it hang loosely.

4. Loosen screws ③ on the upper and lower triple clamps for the left fork leg and remove it.

5. Loosen screws ④ on the upper and lower triple clamps for the right fork leg and remove it.

Installing the fork legs:

1. Position the fork legs. The air bleeder screw ① of the right fork leg should be positioned to the front. Valve A of the left fork leg should face the front. The second milled groove from the top must be flush with the upper edge of the upper triple clamp.

2. Tighten the top triple clamp screws ② to 17 Nm (12.5 lbf ft).

3. Tighten the bottom triple clamp screws ③ to 12 Nm (8.9 lbf ft).

4. Position the brake caliper. Mount and tighten screws ④ to 25 Nm (18.4 lbf ft) with Loctite®243™.

5. Position the brake line and clamp. Mount and tighten screws ⑤.

6. Install the front wheel.

Warning: Incorrect steering head bearing play impairs handling and damages components. Correct it immediately.

Checking Play:

1. Raise the motorcycle with a lift stand.

2. Move the handlebar to the straight-ahead position. Move the fork legs to and fro. There should be no detectable play.

3. If play is detected, adjust the steering head bearing.

4. Move the handlebar through the entire steering range. It must move easily with no detent positions. If detents are detected, adjust the bearing and check/change it if necessary.

Adjusting Play:

1. Raise the motorcycle and remove the handlebar cushion.

2. Loosen top triple clamp screws ①.

3. Remove top steering stem screw ②.

4. Loosen and retighten top steering head screw ③ to 12 Nm (8.9 lbf ft).

5. Using a plastic hammer, tap lightly on the upper triple clamp to avoid stresses.

6. Tighten top triple clamp screws ① to 17 Nm (12.5 lbf ft).

7. Mount and tighten top steering stem screw ② to 20 Nm (14.8 lbf ft) using Loctite®243™.

8. Re-check the steering head bearing play.

9. Mount the handlebar cushion and remove the motorcycle from the lift stand.

Removing the seat:

1. Remove screw ①.

2. Raise the rear of the seat, pull the seat back, and lift it off.

Mounting the seat:

1. Mount the front of the seat on the collar bushing of the fuel tank, lower the seat at the rear, and push the seat forward.

2. Make sure the seat is locked in correctly.

3. Mount and tighten screw ① to 10 Nm (7.4 lbf ft).

Removing the cover:

If the cover is secured:

1. Remove the seat.

2. Remove screw ①.

3. Pull off the air filter box cover in area A sideways and take off toward the front.

If the cover is not secured:

1. Pull off the air filter box cover in area A sideways and take off toward the front.

Installing the cover:

If the cover is to be secured:

1. Insert the air filter box cover in area A and clip it into area B.

2. Mount and tighten screw ① to 3 Nm (2.2 lbf ft).

3. Mount the seat.

If the cover is not secured:

1. Insert the air filter box cover in area A and clip it into area B.

Note: Unfiltered intake air will damage the engine. Only operate with an air filter installed.

Removing the air filter:

1. Remove the air filter box cover.

2. Detach retaining tab ① and remove the air filter with its support.

3. Take the air filter off the support.

Cleaning the air filter and box:

1. Wash the air filter thoroughly in special cleaning liquid (e.g., MOTOREX Racing Bio Dirt Remover) and let it dry properly. Only press the filter to dry it, never wring it out.

2. Oil the dry air filter with a high-grade air filter oil (e.g., MOTOREX Racing Bio Liquid Power).

3. Clean the air filter box and the intake flange, checking for damage and tightness.

Installing the air filter:

1. Mount the clean air filter on the support.

2. Grease the air filter in area A with long-life grease.

3. Insert the air filter, positioning the top retaining pin ① in bushing B.

4. Secure the bottom retaining pin with holding tab ②.

5. Install the air filter box cover.

Warning: The exhaust system gets very hot. Allow it to cool down before working on it.

1. Remove the main silencer from the vehicle.

2. Remove screws ① and pull out the inner tube ②.

3. Remove the old glass fiber yarn filling ③ from the inner tube.

4. Clean the parts and check for damage.

5. Fit the new glass fiber yarn filling ③ into the inner tube.

6. Slide the outer tube ④ over the inner tube with the new filling.

7. Mount and tighten all screws ① to 7 Nm (5.2 lbf ft).

8. Install the main silencer.

Removing the fuel tank:

1. Remove the seat.

2. Turn the fuel tap to the OFF position.

3. Pull off the fuel hose. Be prepared for remaining fuel to flow out.

4. Remove screws ①.

5. Remove screw ② with the rubber bushing.

6. Pull the fuel tank breather hose off the fuel tank lid.

7. Pull both spoilers laterally off the radiator and take off the fuel tank upwards.

Installing the fuel tank:

1. Check the throttle cable routing.

2. Position the fuel tank and fit the two spoilers laterally to the radiator. Ensure no cables are trapped.

3. Attach the fuel tank breather hose.

4. Mount and tighten screw ① with the rubber bushing to 10 Nm (7.4 lbf ft).

5. Mount and tighten screws ② to 10 Nm (7.4 lbf ft).

6. Connect the fuel hose.

7. Mount the seat.

Warning: Incorrect chain tension can damage components and cause accidents.

Cleaning the chain:

1. Raise the motorcycle with a lift stand.

2. Rinse off loose dirt with a soft jet of water.

3. Remove old grease residue with chain cleaner.

4. After drying, apply off-road chain spray.

5. Remove the motorcycle from the lift stand.

Checking chain tension:

1. Raise the motorcycle with a lift stand.

2. Pull the chain upward at the end of the chain sliding piece. The lower chain section must be taut.

3. Measure the chain tension A. It should be 55 … 58 mm (2.17 … 2.28 in). Check at different chain positions.

4. If tension is incorrect, adjust it.

Adjusting chain tension:

1. Raise the motorcycle and check the chain tension.

2. Loosen rear wheel nut ①.

3. Loosen nuts ②.

4. Adjust chain tension using adjusting screws ③ on the left and right. The markings on the chain adjusters must be in the same position relative to reference marks A for correct wheel alignment.

5. Tighten nuts ②.

6. Ensure chain adjusters ④ are fitted correctly on the screws.

7. Tighten rear wheel nut ① to 80 Nm (59 lbf ft).

8. Remove the motorcycle from the lift stand.

1. Raise the motorcycle and shift the transmission to neutral.

2. Check the chain, rear sprocket, and engine sprocket for wear. If any part is worn, change the entire drivetrain kit (chain, front sprocket, rear sprocket).

3. To check chain wear, pull on the top section of the chain with a weight A of 10 … 15 kg (22 … 33 lb.).

4. Measure the distance B over 18 chain rollers in the lower section. The maximum distance should be 272 mm (10.71 in). If it’s greater, change the drivetrain kit.

5. Check the chain sliding guard for wear. If the lower edge of the chain pins is in line with or below the guard, change the guard. Ensure it is firmly seated (tighten screw to 10 Nm (7.4 lbf ft) with Loctite®243™ if loose).

6. Check the chain sliding piece for wear. If the lower edge of the chain pins is in line with or below it, change the piece. Tighten the screw to 15 Nm (11.1 lbf ft) if loose.

7. Check the chain guide minimum thickness C. It should be at least 6 mm (0.24 in). If less, change the guide. Ensure it’s firmly seated and tighten screws if loose.

1. Move the clutch fluid reservoir on the handlebar to a horizontal position.

2. Remove screws ① and cover ② with membrane ③.

3. Check the fluid level. The level should be 4 mm (0.16 in) below the container rim.

4. If the level is incorrect, correct it with Brake fluid DOT 4 / DOT 5.1.

5. Position the cover with the membrane and tighten the screws.

1. Move the clutch fluid reservoir on the handlebar to a horizontal position.

2. Remove screws ①, cover ②, and membrane ③.

3. Fill a bleeding syringe ④ (50329050000) with the appropriate hydraulic fluid (Brake fluid DOT 4 / DOT 5.1).

4. On the clutch slave cylinder, remove bleeder screw ⑤ and mount the bleeding syringe ④.

5. Inject the fluid into the system until it emerges from the drill hole ⑥ of the master cylinder without bubbles. Extract fluid from the reservoir as needed to prevent overflow.

6. Remove the bleeding syringe. Mount and tighten the bleeder screw.

7. Correct the fluid level in the reservoir to 4 mm (0.16 in) below the rim.

8. Position the cover with the membrane and tighten the screws. Clean up any spilled fluid with water.

Checking free travel:

Push the hand brake lever forward and check free travel A. It should be ≥ 3 mm (≥ 0.12 in). If not, adjust the basic position.

Adjusting basic position:

1. Check the free travel of the hand brake lever.

2. Adjust the basic position to your hand size by turning adjusting screw ①. Turn it clockwise to increase the distance from the handlebar, and counterclockwise to decrease it. Do not force it and do not make adjustments while riding.

Warning: Worn-out brake discs reduce braking effect. Replace immediately if worn.

1. Check the front and rear brake disc thickness at multiple points for dimension A.

Brake discs – wear limit

2. If the thickness is less than the specified value, change the brake disc.

3. Check the brake discs for damage, cracking, and deformation. If any of these are present, change the brake disc.

Checking the fluid level:

1. Check the front brake linings first.

2. Move the brake reservoir on the handlebar to a horizontal position.

3. Check the brake fluid level in level viewer ①. If the level has dropped below the marking A, you need to add fluid.

Adding front brake fluid:

1. Move the brake reservoir to a horizontal position.

2. Remove screws ① and take off cover ② with membrane ③.

3. Add brake fluid (DOT 4 / DOT 5.1) to level A, which is 5 mm (0.2 in) below the reservoir rim.

4. Position the cover with the membrane and tighten the screws. Clean up any spills with water.

Checking brake linings:

1. Check the brake linings for minimum thickness A. It should be ≥ 1 mm (≥ 0.04 in).

2. If the thickness is less than specified, or if there is damage or cracking, change the brake linings.

Changing brake linings:

1. Move the brake fluid reservoir to a horizontal position.

2. Remove the cover and membrane. Manually press the brake caliper toward the disc to push back the pistons, extracting fluid from the reservoir if necessary to prevent overflow.

3. Remove cotter pins ④, pull out pin ⑤, and remove the brake linings.

4. Clean the brake caliper and bracket.

5. Check that spring plate ⑥ and brake pad sliding plate ⑦ are seated correctly.

6. Insert the new brake linings (always in pairs), insert pin ⑤, and mount new cotter pins ④.

7. Operate the hand brake lever repeatedly until the linings are in contact with the disc and a pressure point is felt.

8. Correct the brake fluid level to 5 mm (0.2 in) below the reservoir rim.

9. Position the cover with the membrane and tighten the screws. Clean up any spilled fluid.

Checking free travel:

1. Disconnect spring ①.

2. Move the foot brake lever back and forth to check free travel A. It should be 3 … 5 mm (0.12 … 0.2 in).

3. If it does not meet specifications, adjust the basic position.

4. Reconnect spring ①.

Adjusting basic position:

1. Detach spring ①.

2. Loosen nut ② and turn push rod ③ back until you have maximum free travel.

3. To adjust the lever’s basic position, loosen nut ④ and turn screw ⑤ accordingly.

4. Turn push rod ③ until you have the correct free travel A (3 … 5 mm).

5. Hold screw ⑤ and tighten nut ④ to 20 Nm (14.8 lbf ft).

6. Hold push rod ③ and tighten nut ②. Attach the spring.

Checking the fluid level:

1. Check the rear brake linings first.

2. Stand the vehicle upright.

3. Check the brake fluid level in level viewer ①. If the level has dropped below marking A, add fluid.

Adding rear brake fluid:

1. Stand the vehicle upright.

2. Remove screw cap ① with membrane ② and the O-ring.

3. Add brake fluid (DOT 4 / DOT 5.1) to level A.

4. Mount the screw cap with the membrane and O-ring. Clean up any spills with water.

Checking brake linings:

1. Check the brake linings for minimum thickness A. It should be ≥ 1 mm (≥ 0.04 in).

2. If the thickness is less than specified, or if there is damage or cracking, change the brake linings.

Changing brake linings:

1. Position the vehicle vertically.

2. Remove screw cap ① with membrane ② and the O-ring.

3. Manually press the brake caliper toward the disc to push back the piston, extracting fluid from the reservoir if necessary.

4. Remove cotter pins ③, pull out pin ④, and remove the brake linings.

5. Clean the brake caliper and bracket.

6. Check that spring plate ⑤ and brake pad sliding plate ⑥ are seated correctly. The arrow on the spring plate points in the direction of disc rotation.

7. Insert the new brake linings (always in pairs), ensuring decoupling plate ⑦ is on the piston side. Insert pin ④, and mount new cotter pins ③.

8. Operate the foot brake lever repeatedly until a pressure point is felt.

9. Correct the brake fluid level and mount the screw cap. Clean up any spilled fluid.

Removing the front wheel:

1. Raise the motorcycle with a lift stand.

2. Manually press the brake caliper toward the disc to push back the brake pistons.

3. Loosen screw ① by several rotations.

4. Loosen screws ②.

5. Press on screw ① to push the wheel spindle out of the axle clamp, then remove screw ①.

6. Hold the front wheel, remove the wheel spindle, and take the wheel out of the fork.

7. Remove spacers ③.

Installing the front wheel:

1. Check the wheel bearing for damage/wear. If needed, change it.

2. Clean and grease shaft seal rings ① and contact surfaces A of the spacers with long-life grease.

3. Insert the spacers. Clean and grease the wheel spindle.

4. Position the front wheel and insert the wheel spindle, ensuring brake linings are correctly positioned.

5. Mount and tighten screw ② to 35 Nm (25.8 lbf ft).

6. Operate the hand brake lever several times to seat the brake linings.

7. Remove the motorcycle from the lift stand. Operate the front brake and compress the fork a few times firmly to straighten the fork legs.

8. Tighten screws ③ to 15 Nm (11.1 lbf ft).

Removing the rear wheel:

1. Raise the motorcycle with a lift stand.

2. Manually press the brake caliper toward the disc to push back the brake piston.

3. Remove nut ①.

4. Take off chain adjuster ②. Pull out wheel spindle ③ far enough to push the rear wheel forward.

5. Push the rear wheel forward and remove the chain from the rear sprocket.

6. Hold the rear wheel, remove the wheel spindle, and take the wheel out of the link fork.

7. Remove spacers ④.

Installing the rear wheel:

1. Check the wheel bearing for damage/wear. If needed, change it.

2. Clean and grease shaft seal rings ① and contact surfaces A of the spacers with long-life grease.

3. Insert the spacers. Clean and grease the wheel spindle.

4. Position the rear wheel, insert the wheel spindle ②, and mount the chain.

5. Position chain adjuster ③. Mount nut ④, but do not tighten it yet.

6. Ensure chain adjusters ③ are fitted correctly on adjusting screws ⑤.

7. Check and adjust the chain tension.

8. Tighten nut ④ to 80 Nm (59 lbf ft).

9. Operate the foot brake lever repeatedly to seat the brake linings.

10. Remove the motorcycle from the lift stand.

Checking tire condition:

– Check front and rear tires for cuts, run-in objects, and other damage. If found, change the tires.

– Check the tire age. The last four digits of the DOT number indicate the week and year of manufacture. It is recommended to change tires after 5 years at the latest.

Checking tire pressure:

1. Remove the protection cap.

2. Check the tire pressure when the tires are cold.

Offroad tire pressure

3. If the pressure does not meet specifications, correct it.

4. Mount the protection cap.

Warning: Incorrectly tensioned spokes impair handling. Check regularly, especially on a new vehicle.

1. Strike each spoke briefly with a screwdriver blade. You should hear a high note. If you hear different tone frequencies from spokes of equal length and diameter, it indicates different tensions.

2. If spoke tension differs, correct it.

3. Check the spoke torque.

Guideline

Removing the 12-V battery:

1. Remove the seat.

2. Disconnect negative cable ①.

3. Pull back positive terminal cover ② and disconnect the positive cable.

4. Remove screw ③.

5. Pull holding bracket ④ forward and remove the battery upwards.

Installing the 12-V battery:

1. Position the battery (HJTZ5S-FP-C) in the battery compartment with terminals facing forward, and secure with holding bracket ①.

2. Mount and tighten screw ② to 10 Nm (7.4 lbf ft).

3. Connect positive cable ③ to the battery. Tighten screw to 2.5 Nm (1.84 lbf ft). Ensure contact disks A are mounted correctly.

4. Slide positive terminal cover ⑦ over the positive terminal.

5. Connect negative cable ④ to the battery. Tighten screw to 2.5 Nm (1.84 lbf ft).

6. Mount the seat.

1. Remove the seat and the 12-V battery.

2. Check the battery voltage. If it is < 9 V, do not charge the battery; replace it.

3. If the voltage is ≥ 9 V, proceed with charging.

4. Connect a suitable battery charger to the 12-V battery and switch it on.

Guideline for charging:

5. Switch off the charger after charging and disconnect it.

6. Install the 12 V battery and mount the seat.

The main fuse is in the starter relay housing under the seat.

1. Remove the seat.

2. Pull starter relay ① from the holder.

3. Take off protection caps ②.

4. Remove faulty main fuse ③. A faulty fuse has a burned-out fuse wire A. A spare fuse ④ is located in the starter relay.

5. Insert a new main fuse (58011109110 – 10A).

6. Check that the electrical system is functioning.

7. Insert a spare fuse if needed.

8. Mount the protection caps.

9. Mount the starter relay onto the holder and route the cable.

10. Mount the seat.

Warning: Coolant gets very hot. Let the engine and cooling system cool down before opening.

Checking antifreeze and level (engine cold):

1. Stand the motorcycle upright on a horizontal surface.

2. Remove the radiator cap.

3. Check the coolant antifreeze. It should be between -25 … -45 °C (-13 … -49 °F). If not, correct it.

4. Check the coolant level in the radiator. Coolant level A should be 10 mm (0.39 in) above the radiator fins.

5. If the level is incorrect, correct it using the proper coolant.

6. Mount the radiator cap.

Warning: Coolant is hot and toxic. Allow the system to cool and handle with care.

1. Ensure the engine is cold.

2. Remove screw ① and take off radiator cap ②.

3. Place an appropriate container under the water pump cover.

4. Completely drain the coolant.

5. Mount and tighten screw ① with a new seal ring. Torque: 10 Nm (7.4 lbf ft).

6. Position the motorcycle upright.

7. Completely fill the radiator with coolant.

8. Loosen bleeder screw ③ until coolant escapes without bubbles. Then mount and tighten screw ③. Torque: 8 Nm (5.9 lbf ft).

9. Completely fill the radiator with coolant again.

10. Mount radiator cap ②.

11. Allow the engine to warm up and cool down again.

12. Check the cooling system for leaks and re-check the coolant level.

Checking play:

1. Check the throttle grip for smooth operation.

2. With the handlebar in the straight-ahead position, turn the throttle grip back and forth to determine play A. It should be 2 … 3 mm (0.08 … 0.12 in).

3. If the play is incorrect, adjust it.

4. Start the engine and let it run at idle. Move the handlebar to and fro. The idle speed must not change. If it does, adjust the play.

Adjusting play:

1. Remove the seat. If necessary, turn off the fuel tap and remove the fuel tank.

2. Check throttle cable routing.

3. Move the handlebar to the straight-ahead position.

4. Push back sleeve ①.

5. Ensure the throttle cable sleeve is pushed into barrel adjuster ②.

6. Loosen nut ③.

7. Turn barrel adjuster ② to achieve the correct play A (2 … 3 mm).

8. Tighten nut ③ and slide on sleeve ①.

9. Reinstall any removed parts.

1. Screw in idle air adjusting screw ① all the way and turn it to the specified basic setting for your model.

2. Run the engine until warm (≥ 5 min).

3. Adjust the idle speed with adjusting screw ②. The choke function must be deactivated.

Idle speed: 1,400 … 1,500 rpm

4. Turn idle air adjusting screw ① slowly clockwise until the idle speed begins to fall.

5. Note the position and turn the screw slowly counterclockwise until the idle speed again begins to fall.

6. Adjust to the point between these two positions that gives the highest idle speed.

The plug-in connector ① for the ignition timing map is located on the frame under the fuel tank.

Possible states (All SX models & 125 XC US):

– Soft: The plug-in connector is disconnected to achieve better rideability.

– Performance: The plug-in connector is joined to achieve higher performance.

Switching from Performance to Soft:

– Disconnect plug-in connector ①.

Switching from Soft to Performance:

– Join plug-in connector ①.

Checking the position:

Sit on the vehicle in the riding position. The distance A between the upper edge of your boot and the shift lever should be 10 … 20 mm (0.39 … 0.79 in). If not, adjust it.

Adjusting the position:

1. Remove screw ① with the washers and take off shift lever ②.

2. Clean the gear teeth A of the shift lever and shift shaft.

3. Mount the shift lever on the shaft in the required position and engage the gearing.

4. Mount and tighten screw ① with washers. Torque: 14 Nm (10.3 lbf ft) with Loctite®243™.

This work should be done with a cold engine.

1. Turn the fuel tap to the OFF position.

2. Place a cloth under the carburetor to capture draining fuel.

3. Remove screw plug ①.

4. Fully drain the fuel.

5. Mount and tighten the screw plug.

Checking the gear oil level (engine cold):

1. Stand the motorcycle upright on a horizontal surface.

2. Remove gear oil level monitoring screw ①.

3. A small quantity of gear oil must run out of the drilled hole. If not, add gear oil.

4. Mount and tighten the monitoring screw. Torque: 8 Nm (5.9 lbf ft).

Changing the gear oil (engine at operating temperature):

1. Park the motorcycle on a level surface and place a container under the engine.

2. Remove gear oil drain plug ① with magnet and drain plug ②.

3. Let the oil drain fully. Clean the drain plugs and sealing surface.

4. Mount and tighten drain plug ① with a new seal ring. Torque: 20 Nm (14.8 lbf ft).

5. Mount and tighten drain plug ② with a new seal ring. Torque: 15 Nm (11.1 lbf ft).

6. Remove filler plug ③ with the O-ring and fill with 0.80 L (0.85 qt.) of Engine oil (15W/50).

7. Mount and tighten the filler plug with the O-ring.

8. Start the engine and check for leaks, then check the gear oil level.

Adding gear oil (engine cold):

1. Park the motorcycle on a level surface.

2. Remove gear oil level monitoring screw ①.

3. Remove filler plug ② with the O-ring.

4. Add gear oil (15W/50) until it emerges from the drill hole of the monitoring screw.

5. Mount and tighten the monitoring screw. Torque: 8 Nm (5.9 lbf ft).

6. Mount and tighten the filler plug with the O-ring.

7. Start the engine and check for leaks.

Note: Using a pressure cleaner incorrectly can damage components. Maintain a minimum distance of 60 cm (23.6 in) and do not direct the jet at electrical components, connectors, cables, or bearings.

1. Close off the exhaust system to keep water from entering.

2. Remove coarse dirt with a gentle water jet.

3. Spray heavily soiled parts with a motorcycle cleaner and clean with a brush.

4. After rinsing with a gentle spray of water, allow the motorcycle to dry thoroughly.

5. Empty the carburetor float chamber.

6. Remove the closure from the exhaust system.

7. After cleaning, ride the vehicle a short distance until the engine warms up to evaporate water from inaccessible locations.

8. After the motorcycle has cooled down, lubricate all moving parts and pivot points.

9. Clean the chain.

10. Treat bare metal (except brake discs and exhaust) with a corrosion inhibitor.

11. Treat plastic and powder-coated parts with a mild cleaning and care product.

If storing for a longer period:

– When refueling for the last time, add fuel additive.

– Refuel the motorcycle.

– Clean the motorcycle.

– Change the gear oil.

– Check the antifreeze and coolant level.

– Empty the carburetor float chamber.

– Check tire pressure.

– Store the vehicle in a dry location with minimal temperature fluctuations.

– Raise the motorcycle with a lift stand.

– Cover the vehicle with a permeable tarp. Do not use non-porous materials.

– Avoid running the engine for only a short time to prevent rust-causing condensation.

– Remove the motorcycle from the lift stand.

– Perform checks and maintenance measures as you would when preparing for any use.

– Take a test ride.

Brake fluid DOT 4 / DOT 5.1: Use only brake fluid that complies with the specified standard.

Coolant: Use high-grade, silicate-free coolant with corrosion inhibitor additive for aluminum motors. Antifreeze protection to at least -25 °C (-13 °F).

Engine oil (15W/50): Standard JASO T903 MA2, SAE 15W/50.

Engine oil, 2-stroke: Standard JASO FD, fully synthetic.

Fork oil (SAE 4): Standard SAE 4.

Shock absorber fluid (SAE 2.5): Standard SAE 2.5.

Fuel: Super unleaded (ROZ 98 / RON 98 / PON 94) mixed with 2-stroke engine oil in a 1:40 ratio.

Air filter cleaner: MOTOREX® Racing Bio Dirt Remover

Chain cleaner: MOTOREX® Chain Clean

Fuel additive: MOTOREX® Fuel Stabilizer

High viscosity grease: SKF® LGHB 2

Long-life grease: MOTOREX® Bike Grease 2000

Motorcycle cleaner: MOTOREX® Moto Clean

Off-road chain spray: MOTOREX® Chainlube Offroad

Oil for foam air filter: MOTOREX® Racing Bio Liquid Power

Preserving materials for paints, metal and rubber: MOTOREX® Moto Protect

Special cleaner for glossy and matte paint finishes, metal and plastic surfaces: MOTOREX® Quick Cleaner

Special grease (00062010053): Klüber Lubrication® KLÜBERFOOD NH1 34-401

Universal oil spray: MOTOREX® Joker 440 Synthetic