OWNER’S MANUAL 2006 50 SX JUNIOR 50 SX 50 SUPERMOTO ENGLISH ART. NR. 3.211.69EN KTM Group Partner KTM-Sportmotorcycle AG A–5230 Mattighofen www.ktm.
IMPORTANT » Please read this manual thoroughly before letting your youngster ride the motorcycle for the first time. This manual contains important information and recommendations that will help you and your youngster to operate and handle the motorcycle properly.
INTRODUCTION » Now you own a modern motorcycle that you and your youngster will certainly enjoy, provided that you service and maintain it properly. This manual contains important information on the operation and maintenance of your new KTM motorcycle. It went to press describing your model’s latest state of development. Nevertheless, the descriptions may deviate slightly from the current design as our motorcycles are permanently improved.
IMPORTANT WARRANTY AND GUARANTEE INFORMATION » KTM mini-sports motorcycles are designed and constructed to resist the usual wear and tear of normal use in competitions. The motorcycles comply with the regulations and categories currently in effect with the leading international motorcycle associations. The service work specified in the "Lubrication and Maintenance Schedule" must be performed by a KTM workshop and recorded in the service manual otherwise claims under the warranty shall become void.
IMPORTANT INFORMATION FOR PARENTS ABOUT SAFE DRIVING » ENGLISH KTM mini motorcycles are off-road motorcycles designed for one person only. They are not allowed on public roads. The vehicle dimensions and components are designed for children from 4 to 10 years of age with a maximum weight of. 35 kg (78 lbs) and a maximum height of 130 cm (51 in).
TABLE OF CONTENTS » Page Page IMPORTANT INFORMATION FOR PARENTS ABOUT SAFE Changing spring preloading of the shock absorber . . .20 DRIVING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 Check chain tension . . . . . . . . . . . . . . . . . . . . . . . .20 Correct chain tension . . . . . . . . . . . . . . . . . . . . . . .20 SERIAL NUMBER LOCATIONS . . . . . . . . . . . . . . . . . . . .6 Chain maintenance . . . . . . . . . . . . . . . . . . . . . . . . .20 Chassis number . .
SERIAL NUMBER LOCATIONS » Chassis number The chassis number is located on the type plate on the steering head. Enter this number in the field on page no 1. Engine number ENGLISH 6 The engine number is stamped into the right half of the engine case next to the kickstarter. Enter this number in the relevant field on page 1.
OPERATION INSTRUMENTS » Throttle grip The throttle grip is located on the right side of the handlebars. It is used to reduce the engine speed and, thus, the driving speed. The hand brake lever is located on the right side of the handlebars and actuates the front wheel brake. The basic position can be adjusted to fit your child's hand. ENGLISH Hand brake lever 7 Short circuit button 1 The short circuit button [1] turns off the engine. When pressing this button, the ignition circuit is short-circuited.
OPERATION INSTRUMENTS » Choke (Dell’Orto carburetor PHVA 14 DS) Choke lever [1] is mounted to the right side of the carburetor. If you move the choke lever up to the stop, a hole is opened in the carburetor through which the engine can draw in additional fuel. This results in a "rich" fuel-air mixture required for a cold start. Moving the choke lever back closes the hole in the carburetor again.
OPERATION INSTRUMENTS » Plugin - Stand (50 SX, 50 Supermoto) A socket is provided on the left side of the frame for the plug-in stand [1] included in the scope of supply. 1 The damping effect of the rebound damping mechanism can be adjusted by means of the setting wheel [2]. Turn the setting wheel clockwise (in) to increase and counterclockwise (out) to reduce the damping effect. STANDARD SETTING: 5 CLICKS OPEN 2 – NEVER TURN THE SETTING WHEEL MORE THAN TWO CLICKS BETWEEN TWO TEST RIDES.
GENERAL TIPS AND WARNINGS FOR STARTING THE MOTORCYCLE » Instructions for the first ride ENGLISH 10 – Make sure the work for the "pre-delivery inspection" was performed by your authorized KTM workshop. The DELIVERY CERTIFICATE and SERVICE MANUAL will be handed over when you pick up your vehicle. – Before your youngster takes his or her first ride, explain how each of the controls works and check if your youngster has understood what you explained.
DRIVING INSTRUCTIONS » When you start off, the motorcycle must be in a perfect technical condition. For safety reasons, you should make it a habit to perform an overall check of your motorcycle before each start. The following checks should be performed: 1 CHECK TRANSMISSION OIL LEVEL A lack of gear oil leads to premature wear and finally results in destruction of the gear wheels.
DRIVING INSTRUCTIONS » Starting when the engine is cold ENGLISH 1 2 3 4 5 1 12 Open fuel tap [1]. Operate the choke [2]. Kick the side up all the way or remove the plug-in stand. Apply the front brake. Operate the kickstarter, depressing it all the way, without opening the throttle. – WHEN STARTING THE ENGINE, PUT ON MOTORCYCLE BOOTS IN ORDER TO AVOID INJURIES. YOU MAY SLIP OFF THE KICKSTARTER, OR THE ENGINE MAY KICK BACK IF YOU DO NOT KICK HARD ENOUGH.
DRIVING INSTRUCTIONS » The engine speed, and thus the driving speed, are regulated by the throttle grip. The choke must always be deactivated as soon as the engine has warmed up. – AFTER FALLING WITH THE MOTORCYCLE, CHECK ALL ITS FUNCTIONS THOROUGHLY BEFORE USING IT AGAIN. – A BENT HANDLEBAR MUST ALWAYS BE REPLACED. NEVER TRY TO STRAIGHTEN THE HANDLEBAR BECAUSE THIS WILL CAUSE IT TO LOSE ITS STABILITY. – DRIVING A COLD ENGINE AT HIGH SPEED WILL REDUCE THE LIFE OF THE ENGINE.
Service every 5 hours Service every 20 hours 50 SX JUNIOR 50 SX 50 SUPERMOTO Check engine for leaks z z Change transmission oil z z BRAKES CHASSIS Check spark plug, change it if necessary, set electrode gap z Check carburetor for a tight fit at intake flange z Check intake flange for cracks z Check idle setting when engine is warm z Check cooling system for leaks, check quantity of antifreeze z z Check exhaust system for leaks and suspension Check actuating cables for damage, smooth oper
Check transmission oil level z Check cooling liquid level z Check brake fluid level z Check brake pads for wear z Check brake performance z z z Clean and lubricate chain, check tension and readjust it if necessary z ENGLISH Remove and clean dust sleeves of telescopic fork at regular intervals z Clean air filter and filter box Check tire inflation pressure and wear z Check fuel line for leaks z z Drain and clean float chamber Treat exposed metal components (except for the brake and exhaus
MAINTENANCE WORK ON CHASSIS AND ENGINE » MAINTENANCE WORK AND ADJUSTMENTS MARKED WITH AN ASTERISK (*) MUST BE PERFORMED BY AN EXPERT. TO PROTECT YOUR YOUNGSTER, ALWAYS HAVE SUCH WORK PERFORMED BY A SPECIALIZED KTM DEALER WHERE YOUR MOTORCYCLE WILL BE OPTIMALLY SERVICED BY APPROPRIATELY QUALIFIED, SKILLED STAFF. ENGLISH – WHEN CLEANING THE MOTORCYCLE, DO NOT USE A HIGH PRESSURE CLEANING UNIT IF POSSIBLE, OTHERWISE WATER WILL PENETRATE THE BEARINGS, CARBURETOR, ELECTRIC CONNECTORS, DRUM BRAKES, ETC.
MAINTENANCE WORK ON CHASSIS AND ENGINE » Checking and adjusting the steering head bearing (50 SX, 50 Supermoto) * 2 The steering head bearing should be checked regularly for play. To check, support the motorcycle frame and lift the front wheel off the ground. Now try to move the fork back and forth – you should not feel any play. To adjust, loosen both clamping screws [1] on the upper triple clamp and loosen the steering head screw [2] by a few turns.
MAINTENANCE WORK ON CHASSIS AND ENGINE » Basic suspension setup for the weight of the driver AA To achieve maximum handling performance and to prevent the telescopic fork and shock absorber from being damaged, the basic setup of the suspension components must be suitable for your child's weight. At delivery, KTM's mini motorcycles are set to accommodate a driver weighing 25 - 30 kg (wearing full protective clothing).
MAINTENANCE WORK ON CHASSIS AND ENGINE » Telescopic fork maintenance * The telescopic fork must be serviced at least once a year. To service the fork, proceed as follows: Prop up the motorcycle under the frame to take the load off the front wheel. Disassemble the front wheel, remove screw [1] from the brake caliper and unscrew holding clamp. Measure the projection of the fork legs at the upper fork stabilizer and make a note of the measurement.
MAINTENANCE WORK ON CHASSIS AND ENGINE » Cleaning the dust scrabbers of the telescopic fork The dust-protection bellows [1] are to remove dust and coarse dirt particles from the fork tube. However, after some time, dirt may also get in behind the dust-protection bellows. If this dirt is not removed, the oil sealing rings located behind it may start to leak.
MAINTENANCE WORK ON CHASSIS AND ENGINE » General information about KTM disc brakes BRAKE FLUID RESERVOIRS: The brake fluid reservoirs for the front brake is designed such that it does not need to be refilled, even if the brake shoes are worn. If the brake fluid level drops below the minimum level either the brake system has a leak or the brake pads are completely worn. In this case, consult an authorized KTM dealer immediately. A HAVE THE BRAKE FLUID CHANGED AT LEAST ONCE ANNUALLY.
MAINTENANCE WORK ON CHASSIS AND ENGINE » Checking the brake fluid level/ refilling * 1 2 3 ENGLISH 5 mm The brake fluid reservoir is combined with the hand brake cylinder on the handlebar. To check the brake fluid level, press the brake pistons back into the basic position. Move the hand brake cylinder in a horizontal position, remove the screws [1] and the cover [2] with the diaphragm [3]. The brake fluid level should be 5 mm below the upper edge of the reservoir (see drawing), otherwise add DOT 5.
MAINTENANCE WORK ON CHASSIS AND ENGINE » Changing the basic position of the foot brake lever (50 SX Junior) The basic position of the foot brake lever can be changed by unscrewing screw [1] and then turning the retainer [2]. Afterwards, check the setting of the rear wheel brake. 2 Adjusting the control cable on the rear wheel (50 SX Junior) You should be able to press the foot brake lever 5 to 10 mm (0.2-0.4 in) before the rear wheel begins to brake.
MAINTENANCE WORK ON CHASSIS AND ENGINE » Refilling the rear brake fluid reservoir * (50 SX, 50 Supermoto) 1 Remove the screws [1] and take off the cover [2] and diaphragm [3].The brake pistons must be pushed back to their basic position. Fill DOT 5.1 brake fluid (e.g. Motorex Brake Fluid DOT 5.1) up to 8 mm under the upper edge of the reservoir. Remount the diaphragm, cover and screws and actuate the foot brake lever until you feel the point of pressure again.
MAINTENANCE WORK ON CHASSIS AND ENGINE » Removing and mounting the front wheel 1 Jack the motorcycle up by the frame so that the front wheel is suspended above the ground. Undo the hexagon nut [1] and remove it together with the washer. Hold the front wheel and pull out the wheel spindle [2]. Carefully take the front wheel out of the fork. – DO NOT OPERATE THE HAND BRAKE WHEN THE FRONT WHEEL HAS BEEN DISMOUNTED.
MAINTENANCE WORK ON CHASSIS AND ENGINE » Tires, air pressure Tire type, tire condition, and air pressure level affect the way your motorcycle rides, and they must therefore be checked whenever you are getting ready to go anywhere on your motorcycle. – Tire size can be found in the technical specifications. – Tire condition has to be checked every time you want to ride your motorcycle. Before leaving, check tires for punctures and nails or other sharp objects that might have become embedded in them.
MAINTENANCE WORK ON CHASSIS AND ENGINE » Checking coolant level The coolant should be 10 mm (0.4 in) above the radiator fins when the engine is cold (see illustr.). In the event of the coolant being drained, always fill and bleed the system. 10 mm when engine is cold IF POSSIBLE, ALWAYS CHECK LEVEL OF COOLING LIQUID WHEN ENGINE IS COLD. IF YOU HAVE TO OPEN THE RADIATOR CAP WHEN THE ENGINE IS HOT, USE A RAG TO COVER THE CAP AND OPEN SLOWLY TO RELEASE PRESSURE.
MAINTENANCE WORK ON CHASSIS AND ENGINE » A Changing the seat height B The saddle can easily be raised by 25 mm (1 in). This lets you adjust the height as your child grows. Figures A and B show the fork and shock absorber positions for a low seat position. The fork tubes extend approx. 17 mm (0.7 in) (H) above the upper fork stabilizer. The shock absorber is attached to the upper hole in the frame.
MAINTENANCE WORK ON CHASSIS AND ENGINE » Checking the gear oil level To check the gear oil level, first remove the plug [1]. With the motorcycle parked in an upright position, a small quantity of oil should flow out of the indicator opening [2]. If oil must be added, tilt the motorcycle and pour automatic gear oil (Motorex ATF Super) into the bore. 1 2 LESS OIL OR A POOR OIL QUALITY LEAD TO PREMATURE TRANSMISSION WEAR. THEREFORE, ONLY USE BRANDED PRODUCTS (MOTOREX ATF SUPER).
TROUBLE SHOOTING » Adjusting the centrifugal clutch * 1 2 1 1 1 1 1 4 ENGLISH 3 A correctly adjusted centrifugal clutch will provide maximum engine performance and ease of driving and prevent the engine from overheating. Clutch wear can affect the clutch engagement speed. The clutch will slip for a longer period of time at higher clutch engagement speeds, generating more frictional heat and causing the engine to overheat.
TROUBLE SHOOTING » 10 8 NOTE: The centrifugal clutch has an outer diameter of approx. 82.5 mm when new. 11 6 7 To correct slight wear to the surface, you can insert one of the pretensioning disks [11] from each clutch spring between the clutch hub and the clutch shoes – see illustration. If only one disk is installed, you can go ahead and use it. The inner diameter of the centrifugal clutch drum may not exceed 84.4 mm (new condition 84.0 mm). Assemble in the reverse order.
CLEANING » If you let the specified maintenance work on your motorcycle be carried out, disturbances can hardly be expected. Should an error occur nevertheless, we advise you to use the trouble shooting chart in order to find the cause of error. We would like to point out that many operations cannot be performed by oneself. In case of uncertainty, please contact a KTM-dealer.
TECHNICAL DATA – ENGINE » TROUBLE CAUSE REMEDY Engine stalling or running Carburetor overflows if level adjust too high, float Clean carburetor, if necessary replace float needle and with four stroke cycle needle seating is dirty or enlarged adjust level High rpm misfiring Loose carburetor jets Tighten jets Incorrect heat range spark plug or low quality spark plug Refer to technical data section Loose, corroded or non conductive ignition socket Check and seal with silicon connector Engine overheat
CLEANING » Clean your motorcycle regularly in order to keep its painted finish looking shiny and new. The best manner would be to use warm water that has been mixed with a commercially available washing detergent and a sponge. The hard dirt can be removed before with the help of a soft water jet. NEVER CLEAN YOUR MOTORCYCLE WITH A HIGH-PRESSURED CLEANER OR A HIGH-PRESSURED WATER JET, OTHERWISE THE WATER MIGHT RUN INTO THE ELECTRICAL COMPONENTS, CONNECTORS, SHEATHED CABLES, BEARINGS, CARBURETOR ETC.
TECHNICAL DATA – ENGINE » TYP 50 SX JUNIOR Design single cylinder 2-stroke engine, with reed valve inlet 50 SX, 50 SUPERMOTO Displacement 49.0 ccm Bore/Stroke 39.
TECHNICAL SPECIFICATIONS - CHASSIS » 50 SX JUNIOR ENGLISH 36 50 SX 50 SUPERMOTO Frame single downtube, split-cradle Fork Marzocchi Ø = 32 mm Wheel travel front/rear 140/205 mm (5.5/8 in) Rear suspension Central shock absorber WP Front brake Disk brake Ø 160 mm (6.4 in) Rear brake Drum brake Ø 90 mm (3.5 in) Disk brake Ø 140 mm (5.5 in) Tires front 2.50x10” Pirelli MT32A 2.50x12” Pirelli MT32A 90/90-10 Pirelli SL26 Tires rear 2.75x10” Pirelli MT320 2.
HEAD WORD INDEX » Page Page Adjusting the centrifugal clutch . . . . . . . . . . . . . . . . . .30 Filler cap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Adjusting the control cable on the rear wheel (50 SX Junior) .23 Foot brake lever . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 Adjusting the idle speed (Dell’Orto PHBG 19 BS) . . .28 Fuel tap Adjusting the idle speed (Dell’Orto PHVA 14 DS) General information about KTM disc brakes . . . . . . .
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OWNER’S MANUAL 2006 50 SX JUNIOR 50 SX 50 SUPERMOTO ENGLISH ART. NR. 3.211.69EN KTM Group Partner KTM-Sportmotorcycle AG A–5230 Mattighofen www.ktm.
