KTM Supermoto 640LC4 User Manual (English)

Questions and Answers:

A
alexander20Aug 20, 2025
Why does my KTM Supermoto 640LC4 Motorcycle engine overheat?
- K
  Kyle KempAug 20, 2025
  Your KTM Motorcycle engine might overheat due to several reasons. Check the following: * Insufficient cooling liquid: Refill the cooling liquid. * Dirty radiator fins: Clean the radiator with a water jet. * Foam in the cooling system: Replace the cooling liquid, using antifreeze. * Bent radiator hose: Shorten or replace the cooling hose. * Defective thermostat: Remove and check the thermostat or replace it. * Blown fan fuse: Replace the fuse and check if the fan operates properly. * Defective thermoswitch or fan: Check if the fan operates properly by starting the engine and bypassing the connections to the thermoswitch.
R
Rebecca FrenchAug 23, 2025
How to troubleshoot a KTM Supermoto 640LC4 Motorcycle engine that won't reach full power?
- T
  Teresa MarshallAug 23, 2025
  If your KTM Motorcycle engine won't reach full power, the issue could stem from several causes. First, check and clean the fuel system and carburetor. Replace the float and membrane if they are defective. Inspect the vacuum and venting hoses of the carburetor for correct positioning, ensuring there are no kinks. Clean or replace the air filter. Have the valve clearance adjusted and check the setting of the hand decompression cable. Also, have the electronic ignition timing checked. The problem might be caused by a partially interrupted fuel supply, a dirty carburetor, float leaks, a defective membrane of the slide, a leaking carburetor, a very dirty air filter, too small valve clearance, loss of compression, or faulty electronic ignition timing.
E
Edward JensenAug 25, 2025
What to do if my KTM Supermoto 640LC4 Motorcycle engine doesn’t crank?
- L
  lindseywilkinsonAug 26, 2025
  If your KTM Motorcycle engine doesn’t crank, start by turning on the ignition, switching the gear to neutral, and ensuring the emergency OFF switch is on. Then, recharge the battery and investigate the causes of discharging. Also, check the ignition lock and emergency OFF switch. The causes might be operating error, a discharged battery, or a defect in the ignition lock or emergency OFF switch.
C
Christine JohnsonAug 27, 2025
Why does my KTM Supermoto 640LC4 Motorcycle engine fail to idle?
- M
  Mackenzie WrightAug 27, 2025
  If your KTM Motorcycle engine fails to idle, disassemble the carburetor and clean the jets. Have the carburetor adjusted and replace the spark plug. Also, have the ignition system checked. The causes may be a clogged idling jet, incorrect adjustment of adjusting screws on the carburetor, a defective spark plug, or a defective ignition system.
Z
zdeleonAug 30, 2025
What to do if my KTM Supermoto 640LC4 engine does not rev high?
- S
  Summer LopezAug 30, 2025
  If your KTM Motorcycle engine does not rev high, dismount the carburetor and check if it's worn out. Replace the float needle and float if necessary. Adjust the choke cable. Replace the membrane. Check the vacuum hose and venting hose of the carburetor for correct position, ensuring there are no kinks. Tighten the jets and have the ignition system checked. The causes may be a carburetor fuel level that is too high, a dirty or worn-out float needle, a leaking float, the cold starting system being permanently activated, a defective membrane of the slide, a leaking carburetor, loose carburetor jets, or faulty electronic ignition timing.
A
angelicamorrisSep 1, 2025
What to do if my KTM Supermoto 640LC4 Motorcycle engine doesn't crank and the neutral indicator lamp doesn't light up?
- A
  Alyssa WalkerSep 1, 2025
  If your KTM Motorcycle engine doesn't crank and the neutral indicator lamp doesn't light up, replace the fuse located below the headlight mask. Also, remove the seat and replace the main fuse. If the fuse blows again, there may be a more serious issue.
L
Linda DodsonSep 3, 2025
Why does my KTM Supermoto 640LC4 have high oil consumption?
- D
  Dawn JohnsonSep 3, 2025
  If your KTM Motorcycle has high oil consumption, readjust or replace the ventilation hose. Check the engine oil level when the engine is warm and correct if necessary. Use a thicker engine oil. The causes may be a buckling gear ventilation hose, an engine oil level that is too high, or engine oil that is too thin.
A
Alexander WiseSep 5, 2025
What to do if the headlight and parking light fail on my KTM Motorcycle?
- A
  Alex MillerSep 6, 2025
  If the headlight and parking light fail on your KTM Motorcycle, replace the fuse located below the headlight mask. The cause is a blown fuse.
T
thomasdavidSep 8, 2025
Why are the flasher lights, brake light, fan, and horn failing on my KTM Supermoto 640LC4?
- T
  Tammy GeorgeSep 8, 2025
  If the flasher lights, brake light, fan, and horn are failing on your KTM Motorcycle, replace the fuse located below the headlight mask. The cause is a blown fuse.
T
Terrence BlackburnSep 10, 2025
What causes a KTM Motorcycle battery to be discharged?
- W
  William BradshawSep 12, 2025
  If your KTM Motorcycle battery is discharged, check the connections and cables. Recharge the battery according to the instructions. Remove the seat and check the voltage regulator connections. The voltage regulator and generator should be checked. The causes may be loose connections, a defect cable, the ignition not being switched off, or the battery not being charged by the generator.

KTM Supermoto 640LC4 Specifications

General

Engine Type	Single cylinder, 4-stroke
Displacement	625 cc
Bore x Stroke	101 mm x 78 mm
Cooling System	Liquid cooled
Compression Ratio	11.7:1
Transmission	5-speed
Front Suspension	WP USD 48 mm
Rear Suspension	WP monoshock
Front Tire	120/70 R17
Rear Tire	160/60 R17
Seat Height	910 mm
Power	54 hp
Fuel System	Keihin FCR 41
Ignition	Digital
Front Brake	Single disc, 320 mm
Rear Brake	Single disc, 220 mm

Summary

Important Safety and Usage Information

Introduction to Your KTM Motorcycle

Serial Number Locations

Chassis Number

Locates and describes the chassis number for identification.

Engine Number and Type

Details on locating and identifying the engine number and type.

Operation Instruments

Clutch Lever

Explains the operation and adjustment of the clutch lever.

Hand Decompression Lever

Describes the function and usage of the hand decompression lever.

Choke Lever

Details on operating the choke lever for cold starts and its adjustment.

Hand Brake Lever

Explains the function and checks for the hand brake lever.

Speedometer and Indicator Lamps

Description of the speedometer, odometer, and various indicator lamps.

Ignition Lock with 4 Switch Positions

Operation of the ignition lock with four distinct switch positions.

Ignition Lock with 3 Switch Positions

Operation of the ignition lock with three distinct switch positions.

Combination Switch

Explains the functions of the combination switch for lights and horn.

Starter Tip Switch and Emergency OFF Switch

Details on using the starter and emergency off switches for safety.

Filler Cap

Instructions for opening and closing the fuel filler cap.

Fuel

Specifies the type of gasoline required and cautions for its use.

Fuel Tap

Explains the operation of the fuel tap (OFF, ON, RES) and its importance.

Shift Lever

Description of the shift lever and gear position indication.

Kickstarter

Instructions and safety warnings for using the kickstarter.

Foot Brake Pedal

Details on the foot brake pedal and its adjustment.

Fork Compression Damping

How to adjust the compression damping of the front fork.

Fork Rebound Damping

How to adjust the rebound damping of the front fork.

Shock Absorber Compression Damping

How to adjust the compression damping of the rear shock absorber.

Shock Absorber Rebound Damping

How to adjust the rebound damping of the rear shock absorber.

Holding Bars

Describes the passenger holding bars on the rear of the vehicle.

Driving Instructions

Starting the Engine Cold

Step-by-step guide for starting the engine when it is cold.

Starting the Engine Warm or Hot

Procedure for starting the engine when it is warm or hot.

Engine Flooding Procedure

Procedure for starting the engine if it is flooded.

Kickstart Instructions

Detailed instructions and safety for using the kickstarter.

Starting Off

Steps and safety precautions for starting to ride the motorcycle.

Shifting and Riding

Guidance on shifting gears and riding the motorcycle safely.

Braking Instructions

Instructions and safety advice for effective braking.

Stopping and Parking

Procedure for safely stopping and parking the motorcycle.

Center Stand Usage

Instructions and cautions for using the motorcycle's center stand.

Side Stand Usage

Instructions and cautions for using the motorcycle's side stand.

Periodic Maintenance Schedule

Vital Checks and Care Procedures

Maintenance Work on Chassis and Engine

Tool Set

Locates and describes the tool set for maintenance.

Removing the Seat

Step-by-step guide for removing and refitting the motorcycle seat.

Steering Head Bearing Check and Adjustment

Procedure for checking and adjusting the steering head bearing for play.

Shock Absorber Spring Preload Adjustment

How to adjust the spring preload on the rear shock absorber.

Shock Absorber Linkage Lubrication

Instructions for lubricating the shock absorber linkage.

Rear Shock Absorber Rubber Ring Check

Procedure for checking the rubber ring on the rear shock absorber for wear.

Chain Tension Check

How to check and adjust the chain tension for proper operation.

Correct Chain Tension

Details on setting the correct chain tension and wheel alignment.

Chain Maintenance

Guidance on maintaining the X-ring chain for longevity.

Chain Wear Check

Method for checking chain wear and when to replace it.

KTM Disc Brakes Information

General information on KTM disc brakes, calipers, pads, and fluid.

Hand Brake Lever Free Travel Adjustment

How to adjust the free travel on the hand brake lever.

Front Brake Fluid Level Check

Procedure for checking the brake fluid level in the front brake reservoir.

Front Brake Fluid Reservoir Refill

Instructions for refilling the front brake fluid reservoir.

Front Brake Pads Check

How to inspect the thickness of the front brake pads.

Foot Brake Pedal Position Adjustment

Procedure for adjusting the basic position of the foot brake pedal.

Rear Brake Fluid Level Check

Procedure for checking the brake fluid level in the rear brake reservoir.

Rear Brake Fluid Reservoir Refill

Instructions for refilling the rear brake fluid reservoir.

Rear Brake Pads Check

How to inspect the thickness of the rear brake pads.

Front Wheel Dismounting and Mounting (LC4)

Detailed steps for removing and installing the front wheel on LC4 models.

Front Wheel Dismounting and Mounting (LC4 Supermoto)

Steps for removing and installing the front wheel on LC4 Supermoto.

Rear Wheel Dismounting and Mounting (LC4)

Procedure for removing and installing the rear wheel on LC4 models.

Rear Wheel Dismounting and Mounting (LC4 Supermoto)

Steps for removing and installing the rear wheel on LC4 Supermoto.

Rear Hub Shock Absorption Rubbers Check

How to check the shock absorption rubbers in the rear wheel hub for wear.

Tire Pressure and Type

Information on approved tires, types, and correct air pressure.

Spoke Tension Check

How to check and adjust spoke tension for wheel stability.

Battery Maintenance

Details on battery removal, installation, and general care.

Charging the Battery

Procedure and guidelines for charging the motorcycle battery.

Main Fuse Location and Replacement

Locating and replacing the main fuse, with safety precautions.

Individual Fuses

Information on fuses for individual power-consuming units.

Headlight Lamp Exchange

Step-by-step guide for replacing the headlight bulb.

Parking Light Bulb Replacement

Procedure for replacing the parking light bulb.

Brake Light and Tail Light Bulb Exchange

Instructions for replacing brake and tail light bulbs.

Cooling System Overview

Explanation of the cooling system's function and potential overheating causes.

Cooling Liquid Level Check

How to check the cooling liquid level when the engine is cold.

Air Filter Cleaning

Procedure for cleaning the air filter for engine longevity.

Idle Speed Adjustment

How to adjust the engine's idle speed using the adjusting screw.

Throttle Cable Adjustment

How to adjust the throttle cable for correct free play.

Carburetor Float Chamber Draining

Procedure for draining the carburetor float chamber.

Clutch Cable Adjustment

How to adjust the play in the clutch cable.

Choke Cable Play Check and Adjustment

How to check and adjust the choke cable play.

Hand Decompression Cable Adjustment Check

Procedure for checking and adjusting the hand decompression cable.

Engine Oil Specifications

Details on the recommended type and quality of engine oil.

Engine Oil Level Check

Procedure for checking the engine oil level correctly.

Oil Circuit Diagram and Explanation

Diagram and explanation of the motorcycle's oil circulation system.

Oil and Screen Filter Change Procedure

Steps for changing engine oil, filters, and bleeding the oil system.

Oil Filter Change

Procedure for replacing the engine oil filter.

Trouble Shooting

Cleaning Your Motorcycle

Winter Operation Conservation

Storage and Re-initiation

Re-initiation After Storage

Procedure for preparing the motorcycle after a period of storage.

Technical Specifications - Chassis

Technical Data - Engine

Consumer Information for USA Only

Reporting Safety Defects

Procedure for reporting safety defects to NHTSA and KTM.

Noise Emission Warranty

Information regarding the warranty for the exhaust system's noise emissions.

Tampering Warning

Warning against tampering with the noise control system.

Warning Statement

Statement regarding checks for repair or replacement if noise increases.

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