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KTM 50 SX JUNIOR Motorcycle User Manual

1. A brake disk worn down to less than 2 50 mm is a safety risk Have the brake disk replaced as soon as it reaches the service limit Have any repairs on the brake system be performed by a KTM dealer BRAKE CALIPERS Secure the screws on the brake caliper with Loctite 243 and tighten to a torque of 20 Nm Setting the basic position and play of the hand brake lever You can adjust the basic position of the hand brake lever to fit your child s hand by turning stop screw 2 Afterwards be sure to adjust the play of the hand brake lever to 2 mm 0 08 in with the adjusting screw 3 To adjust remove covering cap 4 Replace the covering cap after making the adjust ment S CAUTION At the hand brake lever free travel must at least be 2 mm 0 08 in Only then may the piston in the hand brake cylinder be moved to be recognized by the greater resistance of the hand brake lever If this free travel is not pro vided pressure will build up in the braking system and the front wheel brake may fail due to overheating AND ENGIN Checking the brake fluid level refilling 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
2. Clean fuel pipes examine tank aeration and clean Fit correct spark plug Check intake flange and carburettor if firmly setted Top up coolant and bleed cooling system check cool ing system for leaks Clean radiatar fins with water jet Renew coolant using branded anti freeze anti corro sive Motorex Anti Freeze Drive the motorcycle faster or reduce the preload on the clutch springs Replace with correct routed hoses Readjust to correct ignition timing specifications secure screws with Loctite 243 Measure and adjust compression ratio Check cylinder head replace O ring Correct transmission oil level CLEANING gt gt 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 S CAUTION Never clean your motorcycle with a high pressured cleaner or a high pressured water jet otherwise the water might run into the elec trical components connectors sheathed cables bearings carburetor etc and cause mailfunctions i e lead to the premature destruc tion of these parts You should use commercially available detergents to clean the motorcycle Heavily soiled parts should also be cleaned with the help of a paint brush Before cleaning with water plug the exhaust pipe to prevent
3. If you drive with play in the steering head bearing for longer periods the bearings and subsequently the bearing seats in the frame will be destroyed At least once a year the steering head bearings should be smeared with water proof grease Motorex Long Term 2000 AND ENGIN Checking and adjusting the steering head bearing 50 SX 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 Lift the triple clamp slightly and turn the adjusting nut 3 until hardly any play is left Never tighten the adjusting nut since you might damage the bearing Tighten the steering head screw to a torque of 10 Nm and the 2 clamping screws to 25 Nm AN WARNING re If the steering head bearing is not adjusted to be free of clearance the motor cycle will exhibit unsteady driving characteristics and can get out of control CAUTION The handlebar must move easily Otherwise the bearings will be damaged If you drive with play in the steering head bearing for longer periods the bearings and subsequently the bearing seats in the frame will be destroyed At least once a year the steering head bearings should be smeared with water
4. 000 0 19 PAOLUICSOLID diini i Bare ods e A eae ak 6 Tires air pressure 2 aaa a a 26 To determine the sag of the shock absorber 18 To determine the sag of the telescopic fork 18 Trouble SHOOTIN erer srie Be ea 8 a ee ees 32 What to do when the engine is flooded 12 What you should check before each start 11 ENGLISH INERI E ENGLISH 3211222en LOOZ v YINVENALLIW 0104 KTM Group Partner KTM Sportmotorcycle AG A 5230 Mattighofen www ktm com
5. Check fuel line for leaks Drain and clean float chamber Verify smooth operation of all controls Treat exposed metal components except for the brake and exhaust systems with wax based anti corrosion agents Check all screws nuts and hose clamps for their tight fit at regular intervals el TELE ELE ELL ELE ida 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 CAUTION 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 Before cleaning with water plug the exhaust pipe to prevent water ingress When transporting your motorcycle secure it with elastic straps or other mechanical devices in an upright position Be sure that the fuel tap is closed If the motorcycle topples over fuel can flow out of the carburetor or fuel tank Do not use toothed washers or spring rings with the engine fastening screws as these work into the frame parts and keep working loose Instead use self locking nuts Let your motorcycle cool down before beginning any maintenance work in order to avoid getting burned Dispose of oils fatty matters filters fuels washing detergents etc prop
6. Front rear brake disk Loctite 243 15 Nm Spoke nipple 3 Nm Other chassis screws STANDARD ADJUSTMENT FORK 6 Nm 10 Nm 25 Nm 45 Nm Spring 2 0 N mm Preload 10 mm 0 4 in Fork oll SAE 7 5 Air chamber length STANDARD ADJUSTMENT SHOCK ABSORBER 110 mm 4 3 in 50 SX Junior WP 03189D01 50 SX WP 03189D02 Rebound adjuster 12 10 Spring 75 N mm 35 N mm Spring preload 5 mm 0 2 in 3 mm 0 12 in 6 10 years Adjusting the centrifugal clutch 000 30 Adjusting the control cable on the rear wheel 50 SX Junior 23 Adjusting the idle speed Dell Orto PHBG 19 BS 28 Adjusting the idle speed Dell Orto PHVA 14 DS 28 Adjusting the throttle cable 004 28 Basic suspension setup for the weight of the driver 18 Brake ec tats Seca e hs aia elas he ee es ee oe 13 Chain maintenance 00 20 Changing gear Qil a sche ees ogra AAS Gee Ee 29 Changing spring preloading of the shock absorber 20 Changing the basic position of the foot brake lever BOSA JUNI sec win ks S Bahn a 23 Changing the basic position of the foot brake lever 50 SX 23 Changing the seat height 00000 eae 28 Changing the telescopic fork oil 0 19 Chassis NUMDEE ergorek ot ieee cele 6 Check chain tension 10s caGyes oe hae eee Bee ee we 20 Checking and adjusting the steering head
7. Install tank breather hose 2 without kinks Fuel tap The fuel tap 3 is located at the front of the motorcycle on the left side of the tank Opening the fuel tap Turn the knob all the way to the left Closing the fuel tap Turn the knob all the way to the right Choke Dell Orto carburetor PHVA 14 DS 50SX Junior 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 Choke Dell Orto carburetor PHBG 19 BS 50 SX Choke control knob 2 is mounted to the left side of the carburetor If you pull the choke control knob up to the stop and turn it 90 a hole is opened in the carburetor through which the engine can draw additional fuel This results in a rich fuel air mixture required for a cold start Turning back the choke control knob returns the knob to the starting position and closes the hole in the carburetor again Kickstarter The kickstarter is mounted on the right side of the engine Its upper part can be swivelled Foot brake lever The foot brake lever is located in front of the right footrest The basic posi tion can be adjusted to the seating position see maintenance work Side stand 50 SX Junior Use your foot to swing
8. TA HE W ACT gt N SSA gt Ma Driving 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 AN WARNING After falling with the motorcycle check all its functions thor oughly 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 CAUTION Driving a cold engine at high speed will reduce the life of the engine We recommend to warm the engine up at a medium engine speed for several minutes before switching to full load Never tilt the motorcycle over the side stand to warm up the engine The side stand could fold away and the motorcycle run out of control In the event that while your child is riding on the motorcycle you notice any unusual operation related noise your child should stop immediately turn the engine off and contact an authorized KTM dealer Braking Close the throttle and squeeze both brake levers simultaneously On sandy wet or slippery terrain the rear wheel brake should be preferred The brakes should always be operated carefully as locking wheels can cause skidding or falls AN WARNING Brake drum and linings heat up during brake operation thus reducing the effect of the brakes Wet brakes have reduced brake performance therefore be sure to brake them dry a
9. 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 motor cycle Before leaving check tires for punctures and nails or other sharp objects that might have become embedded in them Regularly check the cold tire pressure Correct tire pressure 1 0 bar 14 psi guarantees optimum grip and maximum tire life A re Damaged tires must be replaced immediately to protect your youngster Worn tires can have a negative effect on how the motorcycle performs especially on wet surfaces Tire pressure below the normal level will lead to premature tire wear Checking spoke tension The correct spoke tension is very important for the stability of the wheels and thus for riding safety A loose spoke causes the wheel to become unbalanced and before long other spokes will have come loose Check spoke tension especially on a new motorcycle at regular intervals If necessary have the spokes retightened and the wheel centered by a KTM dealer A Spokes can tear if you continue to ride with them loose This may lead to an unstable handling of your motorcycle Excessively tensioned spokes may rupture due to local overloading The spokes must be tensioned to 2 5 3 Nm Cooling system The water pump 1 in the engine keeps the cooling liquid in ci
10. explain how the motorcycle will respond to shifting of the rider s weight etc Before starting the motorcycle for the first time check whether the basic fork and shock absorber settings are suitable for your child s weight see chapter on checking the basic chassis setting Before using the motorcycle you should always check all components for proper operation see maine nance schedule Have your youngster perform these technical checks himself herself as well Whenever you go for a ride with your youngster keep in mind that the speed should be adjusted to your youngster and not the other way around Your youngster must understand that all instructions he or she receives from you or any other super vising adult must be followed Your child must be physically ready to ride a motorcycle This means that he or she must at least be able to ride a bicycle Being good at sports that require fast reactions is an additional advantage Your youngster should be strong enough to pick up the motorcycle after a fall Never demand too much of your youngster Give him or her time to get used to the motorcycle and to improve his her riding skills Do not even consider letting your youngster participate in a race before his her physical condition riding skills and motivation have sufficiently developed Explain to your youngster that he she should always adjust his her riding speed to the local condi tions as well as to
11. proof grease Motorex Long Term 2000 How to change the handlebar position The handlebar position can be readjusted by 22 mm 0 9 in The upper triple clamp 4 includes 2 bores arranged at a distance of 15 mm 0 6 in from one another The bores at the handlebar support 5 are offset from the center by 3 5 mm 0 13 in Accordingly you can mount the handlebar in 4 different positions For this purpose remove screws 6 of the handlebar clamps and screws 7 of the handlebar support Position handlebar support and tighten screws 7 to 40 Nm Mount handlebar and handlebar clamps and tighten screws 6 to 20 Nm The gap between the handlebar support and handlebar clamps should be the same size in the front and in the rear i CAUTION The screws 7 must be secured with Loctite 243 YOM DM s lt r Fn Lz a p 7 iii ay i KD AND ENGIN Basic suspension setup for the weight of the driver 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 If your child s weight exceeds or falls short of this range you will need to adjust the spring preload for the telesc
12. speed to recognize and avoid obstacles When riding through curves the rider should also look far ahead into the curve Pay attention to running in procedure ARIIN a Running in Even very precisely machined sections of engine components have rougher surfaces than components which have been slid ing across one another for quite some time Therefore every engine needs to be broken in Do not load the engine to the power limit during the first half hour for this reason Apply low but changing loads for running in NOFULL LOAD OPERATION DURING THE FIRST HALF HOUR AN WARNING Have your youngster wear proper protective gear whenever he or she rides the motorcycle helmet eye protection chest back arm and leg protectors gloves and boots To set a good exam ple be sure to wear protective gear yourself whenever riding a motorcycle The motorcycle has a centrifugal clutch The motorcycle begins to move as soon as the throttle is opened Always apply the front brake when starting the engine and release the brake slowly when the engine is running An activated choke increases the idle speed of the engine the centrifugal clutch thus beginning to engage Therefore the motorcycle can begin to move when the brake levers are released When the engine speed drops to the level at which the cen trifugal clutch disengages braking with the engine is no longer possible and the motorcycle can only be slowed down us
13. 20 Nm Mount brake line and holding clamp Insert fork legs in the fork stabilizers projection as previously noted and tighten clamping screws to 25 Nm top and 10 Nm bottom Mount front wheel see chapter mounting the front wheel AN WARNING The screws 1 must be secured with Loctite 243 Changing the telescopic fork oil Remove front wheel and fork legs see above Remove plugs preload spacers and springs Drain the fork oil into an appropriate container Clean the dust scrabbers AN WARNING re Itis very important to keep the brake disk free from oil and fatty matters Otherwise the braking effect would be strongly reduced After working on the brake system always operate the hand brake lever to apply the brake shoes to the brake disk and have a point of pressure Pour 170 cm3 SAE 7 5 fork oil into each fork tube Slide the fork tube all the way into the slider tube Adjust the air chamber length A to 110 mm 4 5 in by extracting or adding fork oil Insert springs and pretensioning sleeves into the fork tube Check O rings grease and mount plugs Mount the fork legs front wheel and brake caliper see above CICICBDCICS AND ENGIN 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
14. The idle speed can be adjusted with screw 5 The idle speed is increased by turning clockwise The idle speed is reduced by turning counter clockwise AND ENGIN 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 S CAUTION Less oil or a poor oil quality lead to premature transmission wear Therefore only use branded products Motorex ATF Super Changing gear oil The engine must be warmed up before changing the gear oil Park the motor cycle on a horizontal surface remove the oil drain plug 3 and drain the used oil into an appropriate container Clean the sealing surface mount the oil drain plug together with the gasket and tighten to 15 Nm Remove stopper 4 and fill in 0 15 liters of automatic gear oil Motorex ATF Super Mount the stopper and check the engine for tightness i CAUTION Less oil or a poor oil quality lead to premature transmission wear Therefore only use branded products Motorex ATF Super T F 7 te F v i b amp aS is bx LP 2OO AND ENGIN Adjusting the centrifugal clutch A correctly adjusted centrifugal clutch will provide maximum engine perform ance and ease of driving and prevent the en
15. damage smooth operation and kinkless arrangement adjust and lubricate Cc So Lut Cc gt co Cc lt L N oz lt T ari lt Clean air filter and air filter box Check brake fluid level lining thickness brake discs Check the brake line and the brake control cable for damage BRAKES Check function adjust smooth operation free travel of handbrake footbrake levers Check screws of brake system for a tight fit Check suspension strut and fork for leaks and a proper function Check swinging fork pivot Check adjust steering head bearing Check all chassis screws for a tight fit fork plates axle nuts swinging fork pivot Suspension strut Check spoke tension and rim joint Check tire condition and inflation pressure Check chain chain joint chain wheels chain wheel guides for wear a tight fit and tension Lubricate chain Check wheel bearings for play 50 SX JUNIOR 50 SX ADDITIONAL SERVICE WORK TO BE PERFORMED UNDER A SEPARATE ORDER Check the reed type intake valve for wear 20 hours Check the clutch shoes for wear Check the clutch drum for wear Check the water pump shaft and bearings for wear Check the water pump wheel for wear Check the cylinder and piston for wear Check the eccentricity of the crankshaft journal Check the radial clearance of the conrod bearings Check the radial clearance of the piston pin main bearing Check the
16. screws 7 Nm 10 Nm 30 Nm CHASSIS 50 SX JUNIOR Frame Fork single downtube split cradle Marzocchi 32 mm Wheel travel front rear 140 205 mm 5 5 8 in 185 185 mm 7 3 7 3 in Rear suspension Front brake Central shock absorber WP Disk brake 160 mm 6 4 in Rear brake Tires front Drum brake 90 mm 3 5 in Pirelli 2 50 10 33J Scorpion Disk brake 140 mm 5 5 in Pirelli 60 100 12 36NHS Scorpion Tires rear Pirelli 2 75 10 37J Scorpion Pirelli 2 75 10 37J Scorpion Tire pressure Fuel tank capacity 1 8 Liters front rear 1 0 bar Final drive ratio Chain Steering angle 11 48 66 1 2x3 16 96 rolls 10 44 1 2x3 16 102 rolls Wheel base Seat height unloaded 910 mm 35 8 in 585 mm 610 mm 23 24 in 1030 mm 40 in 650 675 mm 25 6 26 6 in Ground clearance Rider s body height Rider s body weight 220 mm 8 6 in max 130 cm 51 in max 35 kg 78 Ibs 255 mm 10 in Recommended age of rider Engine TIGHTENING TORQUES 4 7 years 50 LC Hexagon nuts front rear axle 40 Nm Hexagon nut swing arm bolt 45 Nm Clamping screw upper fork bridge 25 Nm Clamping screw lower fork bridge 10 Nm Screws handlebar clamp 20 Nm Shock absorber top bottom 45 Nm Allan screw Handlebar support Loctite 243 40 Nm Front brake caliper Loctite 243 20 Nm
17. the oil sealing rings located behind it may start to leak For this purpose use a screwdriver to lift the dust scrabbers out of the Slider tubes clean them thoroughly with compressed air spray the fork tubes and dust scrabbers with Universal oil spray Motorex Joker 440 or engine oil Then push the dust protection bellows into the outer tubes by hand AN WARNING OOOO No oil may reach the front tire or the brake disks since this would consider ably reduce the tire s road grip and the braking effect of the front brake Changing spring preloading of the shock absorber This is easily done NOTE Before changing the spring preload note down the basic setting e g how many threads are visible above the adjusting ring Remove the right side cover Loosen the locking ring 2 with the hook spanner Change the spring preload with the adjusting ring 3 and re tighten the locking ring 2 BASIC SETTING SPRING PRELOAD 50 SX Junior 5 mm 0 2 in BO SKE 6 4 ad ded do bh ed 3 3 mm 0 12 in Check chain tension Put the motorcycle on the sidestand Chain tension has to be checked close to the lower rear shock mounting A When pushing the chain upwards the distance to the swingarm has to be 10 mm 0 4 in If necessary correct chain tension A rr If chain tension is too great parts within the secondary transmission chain chain wheels gear box and rear wheel bearings will be subjected to unnec essar
18. the side stand forwards to the stop Make sure it rests securely on solid ground Plugin Stand 50 SX A socket is provided on the left side of the frame for the plug in stand 1 included in the scope of supply Rebound damping function of the shock absorber By using the adjusting screw 2 the degree of damping of the rebound can be adjusted Turn the knob clockwise to increase damping turn it counter clockwise to reduce damping during rebounding STANDARD ADJUSTMENT turn the adjusting screw clockwise to the stop then turn the adjusting screw counterclockwise counting the number of clicks that corresponds to the respective type of shock absorber 5O SX Junior 12 SOSA orere iwe eia enai 10 Never turn the setting wheel more than two clicks between two test rides Do not try to disassemble the shock absorber or to perform maintenance work yourself Danger of injury Ky 5 NXA PINS w LA y 5 S OMe A yr Bid Instructions for the first ride Make sure the work for the pre delivery inspection was per formed 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 under Stood what you explained We recommend to review the entire owner s manual with your yo
19. use a rag to cover the cap and open slowly to release pressure Cleaning the air filter The air filter must be cleaned at intervals depending on the amount of dust accumulated To clean the air filter first remove the seat Then press both retaining clips 1 remove the filter holder and the air filter 2 The air filter consists of a foam rubber insert soaked with filter oil S CAUTION Do not clean the foam filter with fuel or petroleum since these will dam age the foam KTM recommends the products Motorex Liquid Bio Power for air filter maintenance Never operate your motorcycle without an air filter Otherwise dust and dirt may get into the engine and lead to increased wear The holder must retain the air filter throughout its entire circumference If the filter has been mounted incorrectly the engine will take in unfil tered air thereby causing increased engine wear Thoroughly wash the foam filter in special cleaning fluid Motorex Bio Dirt Remover and allow it to dry well Only press out the filter do not wring it out under any circumstances Oil the dry foam filter with a high grade filter oil Motorex Liquid Bio Power Also clean the air filter box Check carbure tor collar for damage and that it Is filled correctly Insert the air filter in the opening and fasten it with the filter holder Then mount the seat Exhaust system The silencer is filled with glass fiber yarn for damping When in us
20. water ingress After the motorcycle has been rinsed with a soft water jet it should be dried by air pressure and a cloth Then take a short drive until the engine has reached its operating temperature and also operate the brakes The heat also causes the water at the inac cessible parts of the engine and the brakes to evaporate Slide back the protective covers on the handlebar mounted instruments so that any water that may have seeped into this part of the motorcycle is allowed to evaporate After the motorcycle has cooled down oil and grease all the gliding bearing parts Also treat the chain with a chain spray To prevent failures in the electric system you should treat the short circuit button with a contact spray If you want to put your motorcycle away for longer periods of time please observe the following instructions Clean motorcycle thoroughly see chapter CLEANING Change engine oil old engine oil contains aggressive contaminations Check antifreeze and amount of cooling liquid the engine warm up again close fuel tap and wait until the engine dies off by itself In this way the carburetor jets are prevented from becoming resin clogged by the old fuel Remove spark plug and fill in approx 5 cc of engine oil into the cylinder through the opening Actuate kickstarter 10 times in order to distribute the oil onto the cylinder walls and mount the spark plug Let fuel flow out of tank i
21. 2008 90 SX JUNIOR 90 SX 3211222en INTRODUCTION gt gt gt Now you own a modern motorcycle that you and your youngster will certainly enjoy provided that you serv ice and maintain it properly Please insert the serial numbers of the motorcycle below Chassis number Engine number Stamp of dealer AIl information contained is without obligation KTM Sportmotorcycle AG particularly reserves the right to modify any equipment technical specifications prices colors shapes materials services service work constructions equipment and the like so as to adapt them to local conditions or to cancel any of the above items all without previous announcement and without giving reasons KTM may stop manufactur ing certain models without previous notice KTM shall not be held liable for any deviations of availabil ity and or ability to deliver illustrations descriptions printing and or other errors The illustrated models partly contain extra equipment which is not applied to standard models 2007 by KTM SPORTMOTORCYCLE AG Mattighofen AUSTRIA All rights reserved Reprint also in extracts with written allowance of KTM SPORTMOTORCYCLE AG Mattighofen only In accordance with the international quality management ISO 9001 standard KTM uses RecNo 121006061 Quality assurance processes that lead to the highest possible product quality INTENDED PURPOSE KTM mini sports motorcycles are designed and constructed to res
22. 7 How to change the handlebar position 17 Important Information for parents about safe driving 4 Instructions for the first ride 00 cease 10 KICKS Sans eked ee he aca es ae ee 8 Maintenance work on chassis and engine 16 Operation instruments 00000 eee 7 Periodic maintenance schedule 4 14 Plugin Stand 50 SX lt lt 0 sesh Saws se ba hae 9 Rebound damping function of the shock absorber 9 Refilling the rear brake fluid reservoir 50 SX 24 Refueling fuel 2 ee 13 Removing and mounting the front wheel 25 Removing and mounting the rear wheel 25 Removing the seat 2 ee 16 Replacing the front brake padS 004 22 Replacing the rear brake pads 50 SX 24 RUONINEIT Se Be a sg Ge Were ca eh oe She ale At ng she Mae ake ag a 10 Serial number locations 0000 eee eee 6 setting the basic position and play of the hand brake lever 21 SAO CCUM DURON sirrane anne Bet det d ee ae et aes 6 DIGG StANG no adr e Beak wide E aa a Mame eke ea 8 SANNE O stare at Panes at each titata ah ook tote E M 12 Starting when the engine is cold 06 12 Starting when the engine is warM 0005 12 StODDING suka eo Mew eh a he ee ea We ee et 13 Storo Es sraa Be eas e eA a So A E 34 Technical data engine 0 aaa 35 Technical specifications chassis 005 36 Telescopic fork maintenance
23. AINTENANCE SCHEDULE MAINTENANCE WORK ON CHASSIS AND ENGINE Removing the seat a acdv ate anaa aw Wa Sat awe a SA Checking and adjusting the steering head bearing 50 SX Junior Checking and adjusting the steering head bearing 50 SX How to change the handlebar position Basic suspension setup for the weight of the driver To determine the sag of the shock absorber To determine the sag of the telescopic fork Telescopic fork maintenance Changing the telescopic fork oil Cleaning the dust scrabbers of the telescopic fork Changing spring preloading of the shock absorber Check chain tension Correct chain tension Chain maintenance General information about KTM disc brakes Setting the basic position and play of the hand brake lever Checking the brake fluid level refilling Checking front brake pads Replacing the front brake padS 04 Changing the basic position of the foot brake lever 50 SX Junior Adjusting the control cable on the rear wheel 50 SX Junior Checking the rear brake linings for wear 50 SX Junior Drum brake maintenance 50 SX Junior Changing the basic position of the brake lever 50 SX Checking the rear brake fluid level 50 SX Refilling the rear brake fluid reservoir 50 SX Checking rear brake pads 50 SX Replacing the rear brake pads 50 SX Removing and mounting the front wheel Removing and mounting the rear wheel Tires
24. LUID 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 BRAKE FLUID We recommend that you use Motorex DOT 5 1 brake fluid when you refill or change the brake fluid DOT 5 1 brake fluid has a wet boiling point of 180 C 356 F 25 C 45 F higher than DOT 4 and is safer for high performance applications Brake fluid DOT 5 1 is a polyethylene glycol based fluid amber colored and can be mixed with DOT 4 brake fluid Do not in any event use DOT 5 brake fluid It is based on silicone oil and is dyed purple KTM motor cycle gaskets and brake hoses are not designed for DOT 5 brake fluid AN WARNING Have the brake fluid changed at least once annually If you wash your motor cycle often the brake fluid should be changed even more frequently Brake fluid tends to absorb water Therefore vapor pockets may form in old brake fluids even at low temperatures causing the brake system to fail BRAKE DISC Due to wear the thickness of the brake disc in the area of the contact face 1 of the brake pads decreases The brake disk must be at least 2 50 mm thick at the thinnest point A Check the thickness of the brake disk at several points AN WARNING re
25. air pressure Checking spoke tension Cooling system Checking coolant level Cleaning the air filter Exhaust system Changing the seat height Adjusting the throttle cable Adjusting the idle speed Dell Orto PHVA 14 DS Adjusting the idle speed Dell Orto PHBG 19 BS Checking the gear oil level Changing gear oil Adjusting the centrifugal clutch TROUBLE SHOOTING CLEANING STORAGE TECHNICAL DATA ENGINE TECHNICAL SPECIFICATIONS CHASSIS HEAD WORD INDEX Page 20 20 20 20 21 21 22 22 22 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 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 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 Hand brake lever 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 Short circuit button The short circuit button 1 turns off the engine When pressing this button the ignition circuit is short circuited Filler cap To open it turn filler cap counter clockwise To close it put filler cap back on and tighten it by turning it clockwise
26. ar wheel Prop up the motorcycle under the frame Remove hexagon nut 3 on the wheel spindle and disk Hold the rear wheel and remove the wheel spindle Move the rear wheel forwards remove chain lift the rear wheel out of the Swinging fork and remove the brake anchor S CAUTION Do not operate the rear brake when the rear wheel has been dismounted Make sure the brake disc is always on top when you lay down the wheel otherwise the brake disc can be damaged 50 SX To mount the wheel reverse the procedure described above Always hook the brake backing plate into the swing arm support Before tightening the hexagon nut of the wheel spindle ensure that the supporting plates 4 are resting against the swing arm Additionally check that the rear wheel is aligned with the front wheel Tighten the hexagon nut to 40 Nm AN WARNING If you don t happen to have a torque wrench at hand make sure you have the tightening torque corrected by a KTM dealer as soon as possible A loose axle may lead to an unstable driving behavior of your motorcycle After mounting the rear wheel keep operating the rear brake until the pres sure point returns 50 SX It is very important to keep the brake disk free from oil and fatty matters otherwise the braking effects would be strongly reduced 50 SX AND ENGIN Tires air pressure Tire type tire condition and air pressure level affect the way your motorcycle rides
27. atio 1 60 when using high grade 2 stroke oil Motorex 2T Cross Power When in doubt please contact your importer Lubrication mixture lubrication Crankshaft bearing 2 grooved ball bearing Connecting rod bearing needle bearing Piston pin bearing needle bearing Piston rings l rectangular ring Primary drive straight cut spur gears 16 57 Z Transmission oil 0 15 0 2 liter automatic gear oil Dexron II Motorex Topspeed 4T 15W50 Spark plug NGK BR 8 ECM Electrode gap 0 6 mm Carburetor Dell Orto PHVA 14 DS Dell Orto PHBG 19 BS Air filter wet foam type air filter insert Cooling liquid BASIC CARBURETOR SETTING 0 5 litres 50 antifreeze 50 distilled water at least 25 C 13 F Model 50 SX Junior 50 SX Type Dell Orto PHVA 14 DS Dell Orto PHBG 19 BS Main jet 80 85 Needle jet 211 FA 260 AU Idling jet 45 48 Jet needle A10 W9 Needle position from top 3 3 Air Mixture reg screw open 3 0 3 0 Slide 40 60 Starting jet 60 60 TIGHTENING TORQUES ENGINE Primary gear nut M14x1 25 40 Nm Hexagon nut ignition rotor M10x1 25 20 Nm Nut of clutch hub M10x1 25 Loctite 243 35 Nm Cylinder head screws M7 15 Nm Cylinder base nuts M8 18 Nm Allan head screw Stator Loctite 243 8 Nm Oil plug 5 Nm Oil drain plug 15 Nm Other engine
28. bearing OSSA JUMO arnericwie tn drei wia te ein ee 16 Checking and adjusting the steering head bearing EELDE O EE E nats raed eaten t ames aan E 17 Checking coolant level 2 0 00 cee eee 27 Checking front brake padS 0 00000 eee 22 Checking rear brake pads 50 SX 2005 24 Checking spoke tension 0 ee ee ee 26 Checking the brake fluid level refilling 22 Checking the gear oil level 000000 29 Checking the rear brake fluid level 50 SX 23 Checking the rear brake linings for wear SOS JUMO asenta aaen Ea ANa 23 Choke Dell Orto carburetor PHBG 19 BS 8 Choke Dell Orto carburetor PHVA 14 DS 8 CEWE aaner stare Ar aan See ST ate a a a 34 Cleaning the air filter 2 2 eee ee 27 Cleaning the dust scrabbers of the telescopic fork 20 Cooling system sid dd ew dea sed a 26 Correct chain tension ssw taenong de hon eww Be Se a 20 DAMN Seite ae atta e ae eaten wo aid b acaten etal fe alee 12 Driving instructions jue ca ai ice eas ac ae torn eRe ae 11 Drum brake maintenance 50 SX Junior 23 Engine number seidteaie aiaa a 6 Exhaust system noana aaa a 27 Page PRICE CAD peranane asa hoe ok ae ede Boone make Bee 7 FOOL DIAKECVEl oiea e ae a a aed 8 CIA sarau hear Ges aay RE A 7 General information about KTM disc brakes 21 General Tips and Warnings for starting the motorcycle 10 Hand brake lever 0 00 eee eee ee
29. ble and poisonous Extreme caution should be used when handling gasoline Never refuel the motor cycle near open flames or burning cigarettes Always switch off the engine before refueling Be careful not to spill gasoline on the engine or exhaust pipe while the engine is hot Wipe up spills promptly If gasoline is swallowed or splashed in the eyes seek a doctor s advice immediately i CAUTION Only use premium grade gasoline ROZ 95 mixed with high grade two stroke engine oil Other types of gasoline can cause engine failure Only use known brands of high grade 2 stroke engine oil Motorex 2T Cross Power Not enough oil or low grade oil can cause erosion of the pis ton when Using too much oil the engine may start smoking and foul the spark plug Fuel expands when its temperature rises Therefore do not fill the tank to the top see fig 50 SX JUNIOR 50 SX Service every Service every 20 hours before every A CLEAN MOTORCYCLE CAN BE CHECKED MORE QUICKLY WHICH SAVES MONEY Check engine for leaks Change transmission oll ENGINE Check spark plug change it if necessary set electrode gap Check the clutch engagement speed Check carburetor for a tight fit at intake flange Check intake flange for cracks Check idle setting when engine is warm Check cooling system for leaks check quantity of antifreeze Check exhaust system for leaks and suspension Check actuating cables for
30. can lead to damage and breakage of the chassis components see chapter on checking the basic chassis setting The use of the motorcycle under extreme conditions e g on extremely muddy and wet terrain can lead to higher than average wear on components such as the drive train or the brakes In this case it may become necessary to service or replace wear parts before the service limit specified in the maintenance schedule has been reached We expressly point out that work marked with an asterisk in the chapter Maintenance work on the chassis and engine must be performed by a KTM workshop If maintenance work should become neces Sary during a competition it must be performed by a trained mechanic Please strictly observe the prescribed running in periods and inspection and maintenance intervals Compliance with these instructions will significantly prolong the life of your motorcycle WARRANTY 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 No claims can be filed under the warranty for damage or consequential damage caused by manipulations or conversions to the motorcycle AUTOMOTIVE FLUIDS The fuels and lubricants specified in the Owner s Manual or automotive fluids with equivalent specifica tions must be used in accordance with the maintenance schedule SPARE PARTS ACCESSORIES For the
31. copic fork Harder fork springs are also available for both models see spare parts catalog AND ENGIN 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 Loosen the clamping screws 2 on the fork stabilizers and pull the fork legs down out of the fork stabilizers i CAUTION Do not operate the hand brake when the front wheel has been dismounted Make sure the brake disc is always on top when you lay down the wheel otherwise the brake disc can be damaged Clamp the fork leg into a vise use protective jaws and remove the plugs 3 Take the preload spacer and the spring out of the fork tube Remove screws 4 at the underside of the slider tubes and pull the fork tubes out of the slider tubes Remove the dust scrabbers 5 Thoroughly clean all parts and check for wear Generously lubricate seals and springs and reassemble the telescopic fork Tighten the screws on the bottom of the sliding tubes to 30 Nm Fill in fork oil and assemble the fork see below Degrease the screws on the brake caliper and apply Loctite 243 Mount the brake caliper and tighten to
32. crankshaft main bearing for wear Replace the crankshaft bearings and conrod bearings Check the entire transmission including bearings for wear Drain and clean the carburetor s float chamber Perform complete fork maintenance Perform complete shock absorber maintenance Clean and lubricate the swinging arm bearing Clean and lubricate the steering head bearing and sealing elements Change brake fluid NOTE Ifthe inspection establishes that permissible tolerances are exceeded the respective components must be replaced The kilometer reading for inspection intervals should not exceed 5 hours Maintenance work performed by your authorized KTM workshop is not a substitute for care and maintenance by the driver NOTE A service hour counter item no SXSO05450600 is available from your KTM dealer for strict observance of the service intervals 50 SX JUNIOR 50 SX VITAL CHECKS AND CARE PROCEDURES TO BE CONDUCTED BY THE OWNER OR THE MECHANIC Check transmission oil level before each start after every cleaning for cross country use Check cooling liquid level Check brake fluid level Check brake pads for wear Check brake performance Lubricate and adjust actuating cables and nipples Remove and clean dust sleeves of telescopic fork at regular intervals Clean and lubricate chain check tension and readjust it if necessary Clean air filter and filter box Check tire inflation pressure and wear
33. e the glass fiber yarn becomes loose or coked with oil carbon This can lead to a power loss and a reduction of the silencer damping The glass fiber yarn packing can be replaced in a few easy steps To replace remove the silencer from the vehicle and mark the position of the outer tube 3 to the inner tube 4 Remove screws 5 and the end cap 6 Pull of the outer tube and remove the old glass fiber yarn packing 7 from the inner tube Thoroughly clean all parts To assemble mount a new glass fiber yarn packing onto the inner tube see illustration and slide into the outer tube Mount end cap and fix with screws 5 Before tightening the screws turn the outer tube until they match the positions you marked Mount the silencer and check the exhaust system for tightness Note Glass fiber yarn packages are offered by your licensed KTM dealer AN WARNING re The exhaust system becomes very hot while the motorcycle is running to avoid burns do not start work on the exhaust system until it has properly cooled down AND ENGIN Changing the seat height 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 Tighten the clamp screws on the fork stabiliz
34. erly Under no circumstances may used oil be disposed of in the sewage system or in the open countryside 1 liter of used oil contam inates 1 000 000 liters of water Removing the seat The quick release mechanism 1 allows removal of the seat without tools Turn the quick release device approximately 180 counterclockwise lift the rear portion of the seat and pull the seat off backwards When mounting the seat ensure that the hook engages at the tank Checking and adjusting the steering head bearing 50 SX Junior The steering head bearing should be checked regularly for play For this purpose jack up the motorcycle by the frame so that the front wheel is in the air Now try to move the fork forward and backward There should be no clear ance For readjustment release the two clamp screws 2 of the top triple clamp and the counternut 3 Turn the adjusting nut 4 until almost no play is left Do not tighten the adjusting nut Tightening the adjusting nut can damage the bearings Keep in mind that tightening the counternut 3 reduces the play of the bearing Slightly tap the top triple clamp with a rubber ham mer to prevent jamming Then tighten the 2 clamp screws with 25 Nm A re If the steering head bearing is not adjusted to be free of clearance the motor cycle will exhibit unsteady driving characteristics and can get out of control S CAUTION The handlebar must move easily Otherwise the bearings will be damaged
35. ers to 25 Nm top and 10 Nm bottom the screw on the shock absorber to 45 Nm Figures A and B low seat position Figures C and D high seat position Figures C and D show the fork and shock absorber positions for a high seat position Fork tubes are plane with top of upper fork stabilizer Screw cap Aluminium protrudes from the top of the upper fork stabilizer The shock absorber is attached to the lower hole in the frame Tighten the clamp screws on the fork stabilizers to 25 Nm top and 10 Nm bottom the screw on the shock absorber to 45 Nm AN WARNING ee The fork tubes may not be lowered any further than as described above oth erwise the clamping on the upper fork stabilizer will no longer be adequate Adjusting the throttle cable There must always be a 3 to 5 mm 0 1 to O 2 in play in the throttle cable To check this move back the protective cover 1 on the throttle grip You must be able to lift the outer covering of the cable 3 5 mm from the adjust ing screw 2 until resistance is felt To adjust loosen the counter nut 3 and turn the adjusting screw accord ingly Finally tighten counter nut and slide the protective cover back on Adjusting the idle speed Dell Orto PHVA 14 DS 50 SX Junior The idle speed can be adjusted with screw 4 The idle speed is increased by turning clockwise The idle speed is reduced by turning counter clockwise Adjusting the idle speed Dell Orto PHBG 19 BS 50 SX
36. eservoir for the rear disk brake Is on the right side of the motorcycle on the rear brake cylinder No air bubble should be visible in inspection glass A when the vehicle is parked in a vertical position AN WARNING Oe If the brake fluid level drops below the upper edge of the inspection glass this indicates that the brake system is either leaking or the brake shoes com pletely worn AND ENGIN Refilling the rear brake fluid reservoir 50 SX 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 10 mm under the upper edge of the reservolr Remount the diaphragm cover and screws and actuate the foot brake lever until you feel the point of pressure again Wipe any overflowing or spilled brake fluid off with water A re Actuate the foot brake lever until you feel the point of pressure again Never use DOTS brake fluid It is based on silicone oil and of a purple color Seals and brake hoses must be especially adapted to it Store brake fluid out of reach of children Brake fluid can cause skin irritation Avoid contact with skin and eyes If you get brake fluid in your eyes rinse with plenty of water and consult a doctor i CAUTION Don t let brake fluid get in contact with paint it is an effective paint remover Use only clean brake fluid taken from a ti
37. fter cleaning If the resistance of the hand brake lever feels unresponsive something is wrong with the brake system Have the brake sys tem checked at a KTM workshop before you let your child drive the motorcycle Stopping Reduce the speed Immediately before the motorcycle comes to a stop put the left foot down To turn off the engine press the short circuit button until the engine stops Close the fuel tap Am Motorcycles produce great heat during operation Therefore keep in mind that the engine the exhaust system and the brakes can heat up considerably Make sure that these parts are not touched and always take care when parking the motorcycle that other per sons will not burn themselves DY EY EV z PD J es ci amp i CAUTION Close the fuel tap when leaving the motorcycle Otherwise the carburetor may get flooded and fuel will enter the engine The side stand or plug in stand is designed to hold the weight of the motorcycle only By sitting on the motorcycle your child will put additional weight on the side stand possibly causing the side stand or frame to be damaged or the motorcycle to fall down Refueling fuel Oil high grade two stroke engine oil must be mixed with the fuel ROZ 95 at a mixing ratio of 1 60 Fuel and engine oil should only be mixed immediately before use KTM recommends Motorex 2T Cross Power ART e Gasoline is highly flamma
38. ghtly sealed container Checking the rear brake pads 50 SX The brake pads can be inspected from the rear The thickness of the linings may not be less than 1 mm 0 04 in A re At their most worn point brake pad linings should not be thinner than 1 mm otherwise they could lead to brake failure For your own safety don t put off having your brake pads changed i CAUTION If the brake pads are replaced too late so that the lining is partly or entirely worn the steel components of the brake pad will rub against the brake disc thereby imparing the braking effect and destroying the brake disc Replacing the rear brake pads 50 SX Dismount the rear wheel see Dismounting the rear wheel Press the brake shoes apart with a suitable screwdriver to allow the brake pistons to return to their basic position Remove the locking screw 4 unscrew the screw 5 and pull the brake shoes out of the brake caliper Slide new brake shoes into the brake caliper a fasten with the screw 5 Tighten the screw to 10 Nm and mount the locking screw 4 Mount the rear wheel and actuate the foot brake lever until you can feel the pressure point AN WARNING Oe 1 Pcie FF NE Itis very important to keep the brake disk free from oil and fatty matters p hs Otherwise the braking effect would be strongly reduced After assembly check if circlips have been fitted correctly After working on the braking system one must alway
39. gine 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 If the clutch engagement speed is too low the engine will not reach the per formance range In both cases the engine will not seem to have enough power Check the clutch engagement speed every 20 hours and correct if necessary or have it corrected by an authorized KTM workshop To tune your clutch lay the bike on the left side To prevent oil from leaking from the transmission vent hose run the hose upwards and fasten Remove the screws 1 and the clutch cover 2 and discard the gasket Block the centrifugal clutch 3 with a suitable driver 4 NOTE insert the driver through both holes in the primary drive s drum and gear wheel Loosen the nut 5 on the clutch and pull out the driver Remove the nut and shim from the crankshaft Screw the extractor special tool item no 590 29 021 044 onto the clutch hub 6 with the M5x50 screws hold the extractor and remove the centrifu gal clutch from the crankshaft by screwing in the extractor screw Completely remove the centrifugal clutch bearings and spacing washers from the crankshaft Loosen the HH screws 7 and remove the clutch shoes 8 from the clutch hub 6 Remove the HH screws and bushings 9 the spring sets 10 and the disks 11 from the clutch s
40. his her own riding skills and that excessive speed can cause falls and severe injuries Always keep in mind that youngsters tend to underestimate dangers or fail to recognize them altogether The riding speed must be reduced in particular on unknown terrain Never let your youngster ride the motorcycle without supervision An adult should always be present The motorcycle is designed for one rider only Your youngster is not allowed to transport a passenger When you go for a ride somebody at home should always know where you are going and when you will be back This makes it easier to send you help should problems occur IMPORTANT INFORMATION FOR PARENTS ABOUT SAFE DRIVING SERIAL NUMBER LOCATIONS Chassis number Engine number auc see 5 5 oe sae oH wee D hee end OPERATION INSTRUMENTS Throttle grip Hand brake lever Short circuit button Filler cap Fuel tap Choke Dell Orto carburetor PHVA 14 DS Choke Dell Orto carburetor PHBG 19 BS Kickstarter Foot brake lever Side stand Plugin Stand 50 SX Rebound damping function of the shock absorber General Tips and Warnings for starting the motorcycle Instructions for the first ride Running in Driving instructions What you should check before each start Starting when the engine is cold Starting when the engine is warm What to do when the engine is flooded Starting off Driving Refueling fuel Braking Stopping PERIODIC M
41. hoes ADJUSTING THE CLUTCH ENGAGEMENT SPEED The spring sets contain 14 spring washers 12 that need to be positioned on top of each other in the order shown in the illustration A Washers are located between the spring sets and the clutch shoes to preten sion the spring sets You can influence the clutch engagement speed by pre tensioning the spring set 0 5 mm more pretension will increase the clutch engagement speed by approx 500 rpm The clutch engagement speed Is the speed at which the clutch begins to engage and the motorcycle starts to drive off The clutch engagement speed is 8500 9000 rpm for the 50 LC engine NOTE atachometer special tool item no 451 29 075 000 to test the clutch engagement speed Is available from your KTM dealer Make sure the spring sets are not soiled during service or repair work to the clutch since this can cause them to malfunction AND ENGIN CORRECTING CLUTCH WEAR Check the clutch shoes for wear If the surface is only slightly worn you can remount them again NOTE The centrifugal clutch has an outer diameter of approx 82 5 mm when new 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 i
42. ing the brakes Your child should never drive faster than its skills and the ter rain permit Never let your child drive its motorcycle unchaperoned Replace the helmet visor or goggle glasses early enough When light shines directly on a scratched visor or goggles you will be practically blind Only use accessory parts recommended by KTM Never leave your motorcycle without supervision as long as the engine is running KTM mini models are designed for one person only Passengers are not allowed These models do not comply with the regulations and safety standards established by the law Therefore they are not per mitted on public roads Always keep in mind that other people feel molested by exces sive noise D What you should check before each start 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 destruc tion of the gear wheels FUEL Check that there is sufficient fuel in the tank when closing the filler cap check that the tank venting hose is free of kinks COOLING FLUID Check the level of cooling fluid when the engine is cold CHAIN A loose chain was fall off the chain wheels an ex
43. isc thereby imparing the braking effect and destroying the brake disc Replacing the front brake pads Remove the front wheel see front wheel chapter Press brake shoes apart with a suitable screwdriver to put the brake pistons in their basic position Remove the lock washer 4 from the screw as well as fixing screw 5 and take the brake shoes out of the brake caliper Clean brake caliper thoroughly with compressed air Mount the left brake shoe and fix with screw Mount the right brake shoe and tighten the screw to 4 Nm Mount the lock washer Align brake shoes mount front wheel see chapter Mounting the front wheel A re It is very important to keep the brake disk free from oil and fatty matters Otherwise the braking effect would be strongly reduced After assembly check if circlips have been fitted correctly Do not unscrew any other screws on the brake caliper or you will have to bleed the brake system After working on the brake system always operate the hand brake lever to apply the brake pads to the brake disk and create a point of pressure AND ENGIN 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 Adjusting the control cable on the rear wheel 50 SX Junior You should be able to press the foot bra
44. ist the usual wear and tear of normal use In competitions The motorcycles comply with the regulations and categories currently in effect with the leading interna tional motorcycle associations OWNER S MANUAL 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 In the interest of everybody involved we urge you to pay particular attention to instructions and information marked as follows ZN WARNING ee Ignoring these instructions can be dangerous to life and limb S CAUTION Ignoring these instructions may damage parts of the motorcycle or impair the motorcycle s traffic safety This manual contains important information on the operation and maintenance of your new KTM motor cycle 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 The Owner s Manual is an integral part of the motorcycle and must be handed over to the new owner when the motor cycle is sold SERVICE Observance of the service maintenance and tuning instructions for the engine and chassis specified in the Owner s Manual is a prerequisite for faultless operation and the avoidance of premature wear An improperly tuned chassis
45. ke lever 5 to 10 mm 0 2 0 4 in before the rear wheel begins to brake The brake control cable is adjusted with adjusting screw 3 on the brake anchor cover First loosen lock nut 4 and then tighten again i CAUTION After making adjustments always make sure the wheel turns freely Checking the rear brake linings for wear 50 SX Junior The brake linings must be replaced when the distance between the hub brake lever and the cable support measured with the brake lever squeezed is less than 50 mm 2 In see illustration i CAUTION If the brake linings are replaced too late i e when the lining is partly or fully worn away the metal shoes will rub against the brake drum thus reducing the braking effect and destroying the brake drum Drum brake maintenance 50 SX Junior Drum brake maintenance is limited to occasional blowing out of the brake drum and brake shoes Brake drum and brake linings can be slightly roughened with an abrasive tape Changing the basic position of the foot brake lever 50 SX The basic setting of the foot brake pedal can be changed by turning the end stop roller 5 Using the push rod 6 the free play on the foot brake pedal must be set Measured on the outside the foot brake pedal must have 3 5 mm of free play before the push rod can move the piston in the brake cylinder to be recog nised from the resistance on the foot brake pedal Checking the rear brake fluid level 50 SX The r
46. n the reverse order Apply Loctite 243 to the HH screws 7 and tighten to 12 Nm Apply Loctite 243 to the M10x1 25 nut 5 on the crankshaft and tighten to 35 Nm Mount a new gasket and position the clutch cover 2 Screw on the clutch cover with 6 M6x25 screws 1 and tighten to 10 Nm Move the transmission vent hose back in the original position TROUBLE SHOOTING gt gt gt gt 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 TROUBLE CAUSE REMEDY Engine fails to start Engine without idle running Operating error The motorcycle was not driven for a longer period of time leaving old fuel in the float chamber Fuel supply interrupted Electrode distance too large Plug fouled by oil wet or bridged Ignition wire or spark plug connector damaged Kill button wire or short circuit switch faulty Loose ignition cable connectors Spark too weak Water in the carburetor and jets blocked Idle adjusting screw out of adjustment Ignition system damaged Wear Open fuel tap replenish fuel do not use choke The highly inflammable components in modern fuels volatilize if left standing for longer
47. ngsters only use the motorcycle within the limits established by the applicable laws making environmental protection one of your top priorities and never violating other people s rights In this spirit we hope that you and your youngsters will always safely enjoy your motorcycle KTM SPORTMOTORCYCLE AG 5230 MATTIGHOFEN AUSTRIA Attachments 1 spare parts manual chassis amp engine B P P CD Fou gt B gt CD P CD pP g g B Fou B g U B gt Fou 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 Ibs and a maximum height of 130 cm 51 in Have your youngster wear proper protective gear whenever he or she rides the motorcycle helmet eye protection chest back arm and leg protectors gloves and boots To set a good example be sure to wear protective gear yourself whenever riding a motorcycle 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 We recommend to review the entire owner s man ual with your youngster item by item paying particular attention to the specially marked warnings and pointing out the danger of Injury Instruct your youngster about riding and falling techniques
48. nto an appropriate basin Correct tire pressure Lubricate bearing points of the control levers footrests etc as well as the chain The storage place should be dry and not be subjected to overly great temperature fluctuations Cover the motorcycle with an air permeable tarpaulin or blanket Do not use airtight materials as possible humidity might not be able to escape and thereby cause corrosion i CAUTION It would be very bad to let the engine run for a short time during the storage period The engine would not get warmed up enough and the thus developed steam would condense during the combustion process and cause the exhaust to rust USE AFTER PERIOD OF STORAGE Fill up tank with fresh fuel Check motorcycle as before each start see driving instructions Take a short careful test ride first NOTE Before you put your motorcycle away for the winter you should check all parts for their function and wear Should any service jobs repairs or any refitting be necessary you should have them carried out during the off season lower workload at mechanics shops This way you can avoid the long waiting times at your shop at the beginning of the next biking season ENGINE 50 SX JUNIOR Design single cylinder 2 stroke engine with reed valve inlet Displacement 49 0 cc Bore Stroke 39 5 40 mm Fuel SUPER fuel research octane no 95 mixed with 2 stroke oil Oil gasoline r
49. opic fork and shock absorber accordingly To adjust check the sag of the shock absorber and telescopic fork The motor cycle should be filled up and your child should be wearing full protective clothing To determine the sag of the shock absorber Jack up the motorcycle until the rear wheel no longer touches the ground Measure the vertical distance between the rear wheel axle and a fixed point e g a mark on the side cover and write it down as dimension A Place the motorcycle on the ground again Have your child sit on the motorcycle in a normal seating position feet on the footrests wearing full protective clothing and bounce up and down a few times to allow the rear wheel suspension to become level Holding your child and the bike have another person measure the distance between the same two points with the load on the motorcycle to establish dimension B The sag is the difference between dimensions A and B EXAMPLE Motorcycle jacked up dimension A 000 eee eee eee 400 mm Motorcycle on ground with driver seated dimension B 355 mm Dd GaGa ewe ees eee eee oe eae Cee ee ee ae 45 mm 50 SX Junior shock absorber sag 0 00000 45 mm 5 mm 50 SX shock absorber sag 0 ee ee 50 mm 5 mm If the sag is lower the spring preload of the shock absorber must be reduced if the sag Is higher the spring preload must be increased see Changing spring preloading of the shock abs
50. orber A harder spring is also available for the 50 SX see spare parts catalog To determine the sag of the telescopic fork Jack up the motorcycle until the rear wheel no longer touches the ground Measure the distance between the upper edge of the slider tube and the triple clamp and write it down as dimension C Have your child sit on the motorcycle in a normal seating position feet on the footrests wearing full protective clothing and bounce up and down a few times to allow the telescopic fork to become level Holding your child and the bike have another person measure the distance between the same two points with the load on the motorcycle to establish dimension D The sag is the difference between dimensions C and D EXAMPLE Motorcycle jacked up dimension C 0000 ee 200 mm Motorcycle on ground with driver seated dimension D 160 mm OAC E E beeen babe ben E oe eee en eee es eee ees 40 mm 50 SX Junior telescopic fork sag ec eee 30 mm 5 mm 50 SX telescopic fork sag oo ee 45 mm 5 mm If the sag is lower the spring preload of the telescopic fork must be reduced if the sag is higher the spring preload must be Increased The preload on the fork spring is determined by the length of preload spacer 1 If an adjustment is necessary demount the fork legs remove the plugs and shorten the pretensioning sleeves or replace with longer ones see maintenance of teles
51. periods of time If the motorcycle has not been used for over 1 week the fuel should be drained from the float chamber The engine will start up immediately if the float chamber is filled with fresh ignitable fuel Close fuel tap loosen fuel hose at carburettor lead into a basin and open fuel tap if fuel leaks out clean carburettor if no fuel leaks out check tank ventilation i e clean fuel tap Reduce electrode distance 0 60 mm Clean spark plug or renew Dismount spark plug connect ignition cable hold to ground blank place on engine and actuate kickstarter a strong spark must be produced at the spark plug f no spark is produced loosen spark plug cap from igni tion cable hold about 5 mm from ground and actuate kick Starter f a spark now occurs replace spark plug cap f no spark is produced control ignition system Disconnect black coloured cable from short circuit button at ignition coil and check ignition spark If the spark is O K repair defective part of cable or ignition switch Inspect cable connectors Examine ignition system Dismantle and clean carbureto Readjust idle running or replace idle adjusting screw Examine ignition system Overhaul engine Less power of engine Air filter obstructed Fuel supply partly interrupted or blocked Loss of compression due to loose spark plug Exhaust system damaged Engine has not enough preignition Reed paddles tensionless o
52. r damaged sur face of reed valve housing damaged Wear Clean or renew airfilter Blow through fuel pipe and clean carburetor Tighten spark plug Check exhaust system for damage Check and adjust ignition Replace reed paddles or reed valve housing Overhaul engine TROUBLE CAUSE REMEDY Engine stalling or running with four stroke cycle Carburetor overflows if level adjust too high float needle seating is dirty or enlarged Loose carburetor jets Clean carburetor if necessary replace float needle and adjust level Tighten jets High rpm misfiring Incorrect heat range spark plug or low quality spark plug Loose corroded or non conductive ignition socket connector Refer to technical data section Check and seal with silicon Engine spluters into the car buretor Engine overheating Emission of white smoke steam Excessive oil escapes from transmission breather tube Lack of fuel Spark plug with incorrect heat value Ignition by incandescence Engine takes air out of control Insufficient liquid in cooling system Radiator fins clogged Frothing in cooling system The motorcycle is being driven too slowly the clutch keeps slipping causing heat to develop Pinched or kinked water hoses Incorrect ignition timing because of loose stator screws Incorrect compression ratio Cylinder head or O ring of cylinder head gasket leaks Excessive oil quantity in transmission
53. rculation The cooling liquid is cooled by the air stream Therefore the cooling effect is reduced when the traveling speed is reduced Dirty radiators additionally reduce the cooling effect The cooling liquid can be drained by removing screw 2 on the water pump cover AN WARNING Do not remove any cooler hoses or the drain screw when the engine is hot A mixture of 50 antifreeze and 50 distilled water is used as the cooling liquid How ever the antifreeze protection must be at least 25 C 13 F This mixture offers antifreeze protection but also good corrosion protection and should therefore not be replaced by pure water i CAUTION For the cooling system use only with high grade antifreeze Motorex Anti Freeze Using lower grade antifreeze agents can cause corrosion and coolant foaming Pressure induced by heating of the coolant in the system is controlled by a valve in the radiator cap 3 a water temperature rising up to 120 C 248 F is admissible without fear of problems IAUATAUETAYOOA OOOO OO UAN OTCOVU ODOTIN 10 mm when engine is cold AND ENGIN 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 AN WARNING OOOO 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
54. re poisonous and can cause loss of consciousness and death Always pro vide adequate ventilation while the engine is running S CAUTION Don t ride your motorcycle with full load and high revs when engine is cold Because the piston is warming up faster than the water cooled cylinder it can cause engine damage NOTE The highly inflammable components in modern fuels volatilize if left stand ing for longer periods of time If the motorcycle has not been used for over 1 week the fuel should be drained from the float chamber The engine will start up immediately if the float chamber is filled with fresh ignitable fuel Starting when the engine is warm 1 Open fuel tap 1 2 Kick the side up all the way or remove the plug in stand 3 Apply the front brake 4 Operate the kickstarter depressing it all the way without opening the throt tle What to do when the engine is flooded 1 Close fuel tap 1 2 Applying the front brake 3 Start engine with full throttle If necessary unscrew spark plug and dry it 4 Once the engine is running open fuel tap again Starting off Slowly release the brake lever while simultaneously opening the throttle AN WARNING OOOO Always make sure the side stand is kicked all the way up or the plug in stand removed before you let your child drive off The motorcycle could run out of control if the stand touches the ground Sy K Dy x yy OS gt tes zy PPN te DD
55. s actuate the hand brake lever or foot brake lever respectively so as to ensure that the brake pads will lie against the brake disk and the pressure point is established AND ENGIN Removing and mounting the front wheel 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 i CAUTION Do not operate the hand brake when the front wheel has been dismounted Make sure the brake disc is always on top when you lay down the wheel otherwise the brake disc can be damaged Lift the front wheel into the fork and correctly position it Mount the wheel spindle 2 Mount the washer and the hexagon nut 1 and tighten 40 Nm Put the motorcycle back on the ground and operate the front wheel brake until the working point is reached A re If you don t happen to have a torque wrench at hand make sure you have the tightening torque corrected by a KTM dealer as soon as possible A loose axle may lead to an unstable driving behavior of your motorcycle After mounting the front wheel keep operating the hand brake until the pressure point returns It is very important to keep the brake disk free from oil and fatty matters eitherwise the braking effects would be strongly reduced Removing and mounting the re
56. safety of your child only use spare parts and accessories approved by KTM KTM shall not assume any liability for other products or consequential damage resulting from the use of such products When special needs arise please contact a KTM dealer who will seek the assistance of the KTM importer if necessary SAFETY Parents should keep in mind that the safety of their youngsters always depends on the efforts made by the parents to ensure that the motorcycle is kept in good working order and only used on safe terrains Nevertheless driving the motorcycle like driving any other vehicle involves a potential risk Therefore please make sure that all fundamental precautions are taken Please also read the INFORMATION ON SAFE DRIVING FOR PARENTS on page 4 TRANSPORT When transporting your motorcycle secure it with elastic straps or other mechaical devices in an upright position Be sure that the fuel tap is closed If the motorcycle topples over fuel can flow out of the car buretor or fuel tank ENVIRONMENT Riding an off highway motorcycle is a wonderful form of outdoor recreation and we certainly hope that you and your youngsters will enjoy it to the full However this enjoyable outdoor activity can cause envi ronmental problems or lead to conflicts with other people Responsible use of the motorcycle will prevent such problems and conflicts You can contribute to securing the future of motorcycling by making sure that you and your you
57. the reservoir see drawing otherwise add DOT 5 1 brake fluid e g Motorex Brake Fluid DOT 5 1 up to 5 mm below the upper edge of the reservoir Mount the diaphragm the cover and the screws and actuate the hand brake lever until you feel the point of pressure again Wipe off any overflowing or spilled brake fluid with water AN WARNING OOOO Actuate the hand brake lever until you feel the point of pressure again Never use DOT 5 brake fluid It is based on silicone oil and of a purple color Seals and brake hoses must be especially adapted to it Store brake fluid out of reach of children Brake fluid can cause skin irritation Avoid contact with skin and eyes If you get brake fluid in your eyes rinse with plenty of water and consult a doctor i CAUTION Don t let brake fluid get in contact with paint it is an effective paint remover Use only clean brake fluid taken from a tightly sealed container Checking front brake pads Inspect the brake pads from in front of the vehicle The linings must be at least 1 mm 0 04 in thick AN WARNING OO At their most worn point brake pad linings should not be thinner than 1 mm 0 04 in otherwise they could lead to brake failure For your own safety don t put off having your brake pads changed S CAUTION If the brake pads are replaced too late so that the lining is partly or entirely worn the steel components of the brake pad will rub against the brake d
58. tremely worn chain may tear and insufficient lubrication may result in unnecessary wear of the chain and chain wheels TIRES Check for damaged tires Tires showing cuts or dents must be replaced Also check the air pressure Insufficient tread and incorrect air pressure deteriorate the driving performance BRAKES Check for proper functioning check brake fluid level in the tank The tank is designed such that it does not need to be refilled even if the brake shoes are worn If the brake fluid falls below the minimum level the brake system is either leaking or the brake shoes are completely worn out Have the brake system checked at a KTM workshop to avoid brake failure Also have the condition of the brake hose and the brake lining thickness checked Check the play of the hand brake lever and foot brake lever THROTTLE CABLE Check the throttle cable for proper adjustment and smooth operation D A Starting when the engine is cold 1 Open fuel tap 1 2 Operate the choke 2 3 Kick the side up all the way or remove the plug in stand 4 Apply the front brake 5 Operate the kickstarter depressing it all the way without opening the throt tle AN WARNING Oe 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 Do not start the engine and allow it to idle in a closed area Exhaust fumes a
59. ungster item by item paying par ticular attention to the specially marked warnings and point ing out the danger of Injury Adjust the basic position of the hand brake lever to fit the size of your child s hand You child should of course wear gloves Adjust the foot brake lever to your child s seating position To prevent injury teach your youngster the basic riding skills on soft ground e g on a meadow or in the garden Be sure that there is room enough to maneuver and that no other rid ers are close To ensure that your youngster gets the feel of the brakes have your youngster operate the brakes while you push the motor cycle Do not start the engine before your youngster has learned to apply both brakes with appropriate pressure Now your youngster must get the feel of the throttle Start the engine hold the motorcycle and have your youngster slowly open the throttle Then your youngster can take his her first ride Initially your youngster should ride back and forth between two persons who help the young rider to stop the motorcycle However you should also teach your youngster how to stop the motorcycle himself herself To improve his her riding skills your youngster should practise to ride the motorcycle standing on the footpegs or riding at the slowest possible speed Additionally you can arrange a series of obstacles and have your youngster drive around them etc Tell your youngster to look 3 10 m ahead depending on the
60. y stress resulting in premature wear and even chain breakage Too much slack in the chain on the other hand can result in the chain jumping off the chain wheels If this happens the chain could also block the rear wheel or damage the engine In either case the operator is likely to lose control of the motorcycle Be careful not to get your finger caught between the chain and the rear sprocket or other components Correct chain tension Release the hexagon nut of the wheel spindle 4 and turn the left and the right hexagon nut 5 equally far Before tightening the hexagon nut of the wheel spindle to 40 Nm ensure that the supporting plates 6 are resting against the swing arm Additionally check that the rear wheel is aligned with the front wheel Chain maintenance For long chain life good maintenance is very important Chains without O rings should be cleaned in fireproof solvent regularly and afterwards treated with hot grease or chain spray Motorex Chainlube Racing AN WARNING OOO Keep the rear wheel free of grease Grease on the rear wheel will significantly reduce the grip of the rear tire and the motorcycle could easily get out of control i CAUTION When mounting the chain masterlink clip the closed side of the masterlink clip must point in running direction Also check sprockets and chain guides for wear and replace if necessary AND ENGIN General information about KTM disc brakes BRAKE F

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