250-525 SX, MXC, EXC RACING REPAIR MANUAL ENGINE KTM SPORTMOTORCYCLE AG 5230 Mattighofen Austria www.ktm.
250-525 SX, MXC, EXC RACING REPAIR MANUAL ENGINE
1 SERVICE-INFORMATIONS 2 GENERAL INFORMATION 3 REMOVING AND REFITTING ENGINE 4 DISASSEMBLING ENGINE 5 SERVICING INDIVIDUAL COMPONENTS 6 ASSEMBLING ENGINE 7 ELECTRICAL 8 FUEL SYSTEM 9 TECHNICAL SPECIFICATIONS 10 PERIODIC MAINTENANCE SCHEDULE 11 WIRING DIAGRAMS 12 13 14 15 16
I M P O RTA N T I N F O R M AT I O N /U P D AT I N G INSTRUCTIONS To be able to continue using the existing loose-leaf repair instructions, simply print the following pages and insert them in the existing repair instructions: Art.-No.
E X P L A N AT I O N - U P D AT I N G 3.205.85-E Repair Manual 400/520 SX, MXC, EXC RACING Basic version Model year 2000 (Engine number with first digit “0“) 2/2000 3.210.01-E Updating of Rep.Manual 3.205.85-E Model year 2001 (Engine number with first digit “1“) Art.-No. 3206007 -E 1/2001 3.210.44-E Updating of Rep.Manual 3.205.85-E Model year 2002 (Engine number with first digit “2“) 2/2002 3.206.007-E Updating of Rep.Manual 3.205.
INTRODUCTION This repair manual offers extensiv repair-instructions and is an up-to-date version that describes the latest models of the series. However, the right to modifications in the interest of technical improvement is reserved without updating the current issue of this manual. A description of general working modes common in work shops has not been included. Safety rules common in the work shop have also not been listed.
REPLY FAX FOR REPAIR MANUALS We have made every effort to make our repair manuals as accurate as possible but it is always possible for a mistake or two to creep in.
2-1C 2 GENERAL INFORMATION INDEX Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No. 3206007 -E OIL CIRCUIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ENGINE OIL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CHECKING THE ENGINE OIL LEVEL . . . . . . . . . . . . . . . . . CHANGING THE ENGINE OIL . . . . . . . . . . . . . . . . . . . . . . CHANGING THE OIL FILTERS . . . . . . . . . . . . . . . . . . . . . .
2-2C 4 3 7 6 5 8 11 10 13 1 12 Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No. 3206007 -E 9 2 Oil circuit Via the long oil screen 2, the oil pump 1 draws engine oil from the oil sump of the transmission. This engine oil flows through an oil line 3 into the cylinder head for camshaft lubrication 4; the oil quantity is controlled by the jet bolt 5. An oil duct branches off to the long oil filter 6 where the coarser particles contained in the engine oil are filtered away.
2-3C Engine oil Only use fully synthetic brand oils (Motorex Power Synt. 4T) that meet or surpass the quality requirements of API classes SG or SH (see specifications on the container). API: SG, SH TEMPERATURE – 10W 40 10W 50 0°C 32°F + ! INSUFFICIENT THE ENGINE. CAUTION ! AMOUNTS OR LOW-GRADE ENGINE OIL LEAD TO PREMATURE WEAR OF 15W 40 15W 50 Checking the engine oil level The engine oil level can be checked with the engine being either warm or cold.
2-4C Changing the engine oil 1 NOTE: When changing the engine oil, it is necessary to clean the short and long oil screens and to replace both oil filters. Engine oil has be changed with the engine being at an operating temperature. WARNING AN ENGINE AT OPERATING TEMPERATURE AND THE ENGINE OIL IT CONTAINS ARE VERY HOT - DO NOT BURN OR SCALD YOURSELF! Place the motorcycle on a horizontal surface, remove the plug 1 and allow the oil to drain into a receptacle. Clean plug (with magnet) thoroughly.
2-5C Changing the oil filters 1 Remove the bolt 1 and swing the brake fluid container sideward. Place a receptacle underneath the engine to collect the drained oil. Remove the 4 bolts 2 and dismount the two oil filter covers. 2 2 2 2 Using circlip pliers, you may now pull the oil-filter inserts 3 out of the housing. Clean the oil filter cover, the sealing surfaces of the O-rings and the engine casing. Check the O-rings of the oil filter covers for damage and, if necessary, replace them.
2-6C 1 2 Checking the oil level of the hydraulic clutch To check the oil level in the master cylinder of the clutch remove the cover. For this purpose, remove bolts 1 and cover together with the rubber boot 2. The oil level in the horizontal-standing master cylinder should be 4 mm (0,157 in) below the upper edge. If necessary add SAE 10 biodegradable hydraulic oil. ! CAUTION ! ONLY USE SAE 10 BIODEGRADABLE HYDRAULIC OIL TO REFILL THE MASTER CYLINDER.
2-7C 4 2 19 18 1 10 8 21 9 7 13 12 20 11 16 6 17 3 15 14 24 5 22 23
2-8C SPECIAL TOOLS – ENGINE FIG 1 2 3 4 5 6 7 8 Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No. 3206007 -E 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 PART NO. 560.12.001.000 590.29.002.000 590.29.020.000 590.29.005.010 510.12.011.000 590.29.021.000 598.29.015.075 580.12.015.089 580.12.015.095 6 899 785 584.29.059.000 151.12.017.000 151.12.018.000 151.12.018.100 590.29.026.006 590.29.035.000 590.29.036.000 590.29.033.000 590.29.019.000 584.29.037.037 590.29.034.000 580.12.009.
2-9C CLEANING Clean your motorcycle regularly in order to maintain the beauty of its plastic surfaces. The best manner would be to use warm water that has been mixed with a normal brand-name washing detergent and a sponge. The hard dirt can be removed before washing with the help of a soft water jet. ! CAUTION ! NEVER CLEAN YOUR MOTORCYCLE WITH A HIGH-PRESSURED CLEANER OR A HIGH-PRESSURED WATER JET.
3-1C DISMOUNTING AND MOUNTING THE ENGINE INDEX Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No. 3206007 -E DISMOUNTING THE ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . MOUNTING THE ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BLEEDING THE COOLING SYSTEM . . . . . . . . . . . . . . . . . . . . . . CHECKING THE ADJUSTMENT OF THE HAND DECOMPRESSION RELEASE CABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ADJUSTING THE THROTTLE CABLES . .
3-2C Dismounting the engine – Clean the motorcycle thoroughly and prop it up on a stable stand. – Dismount the seat and the tank with spoilers. – Disconnect the ground cable 1 of the battery. 1 – Remove the screw 2 and detach the 2 tension springs 3. 2 3 – Detach the 2 tension springs 4, pull exhaust pipes forward and take them off the vehicle. Art.-No. 3206007 -E 4 – Detach the 2 tension springs 6 and remove the screw 5. – Pull the intermediate pipe forward and take it off the vehicle.
3-3C – Remove the carburetor cover and unhitch both throttle cables. – Detach the return spring 1 of the footbrake pedal. – Remove the 2 screws 2 and take off the frame cover. 2 1 – Open the radiator cap. – Remove the screw 3 at the cylinder together with the sealing ring and drain the coolant into a receptacle. 5 – Disconnect the water hoses 4 and 5. – Disconnect the hose of the engine ventilation system 6. 6 4 3 – Disconnect the plug-in connection from the throttle-valve sensor.
3-4C – Remove the bolts 1 and take off the sprocket cover. – Remove the 2 bolts 2 of the clutch slave cylinder and pull the clutch slave cylinder off the casing. 1 1 – Swing the chain damper plate backwards. – Open the chain joint and remove the chain from the vehicle. 2 – Remove the bolt 3 and take off the cable clip. NOTE: From Model 2001 onwards a cable tie is mounted instead of the the cable clip. 3 – Disconnect the radiator hose 4 and dismount the tank roller 5. Art.-No.
3-5C Mounting the engine – The engine is mounted exactly the reverse order. Be sure to use the correct fastening torques (see technical specifications). – After a short, careful test ride, check engine oil and coolant level once more. Bleeding the cooling system To bleed the cooling system, fill in approx. 0.8 liters (0.2 US gallons) of coolant and remove the bleeder bolt 1. Do not reinstall the bleeder bolt until coolant escapes at the bore without any bubbles.
4-1C DISMANTLING THE ENGINE Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No. 3206007 -E INDEX DRAINING THE ENGINE OIL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2 DISMOUNTING THE OIL FILTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2 DISMOUNTING THE CHAIN WHEEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2 DISASSEMBLING THE CLUTCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-2C Draining the engine oil 2 – Remove the bolts 1, 2, and 3, and drain the engine oil into a receptacle. – Remove kickstart and shift lever. 3 1 Dismounting the oil filter – Unfasten the 4 bolts and remove both oil filter covers 4. 4 4 – Pull the 2 oil filters out of the housing. Art.-No. 3206007 -E NOTE: To pull out the oil filters, you should use circlip pliers (see photo).
4-3C Disassembling the clutch – Loosen all bolts of the clutch cover and dismount clutch cover together with gasket. – Pull the 2 dowels out of the engine casing. – Loosen the bolts in a crosswise order to prevent the clutch discs from getting jammed when the clutch springs are released. – Dismount the pressure cap together with bolts, spring retainer, and clutch springs. – Remove the pressure piece 1. – Take all lining and steel discs out of the outer clutch hub.
4-4C – Turn crankshaft to TDC. A NOTE: In the TDC position, the guidepiece A will be above the pulser coil (see photo). – Turn out the crankshaft fixing bolts 1 and remove the sealing ring 2. – Turn in the crankshaft fixing bolt by hand. – If you feel any resistance, move the flywheel slightly back and forth so that the crankshaft fixing bolt may engage the recess of the crankshaft. – Tighten the crankshaft fixing bolt to 10 Nm/8 ft.lb. 1 2 – Loosen the collar nut 3 and remove the spring washer.
4-5C – Apply the special tool as shown, loosen the collar nut from the primary gear and remove. – Remove the special tool. ! CAUTION ! COLLAR NUTS WITH LEFT-HAND THREAD AND WITH RIGHT-HAND THREAD WERE USED RESPECTIVELY. COLLAR NUTS LABELED AS "LEFT" HAVE A LEFT-HAND THREAD. COLLAR NUTS WITHOUT LABELING HAVE A RIGHT-HAND THREAD. – – – – Turn the crankshaft to the TDC position (see illustration on page 4-4C). Turn out the crankshaft fixing bolts 1 and remove the sealing ring 2.
4-6C From the 2003 model: – Remove the outer clutch hub 1 together with the stepped disk 2 and both half disks 3 from the main shaft. 3 2 – Remove both needle bearings 4 and the supporting plate. 1 2 3 4 Dismounting the oil pump Art.-No. 3206007 -E – Loosen the 2 bolts 5 and remove the oil pump cover. 5 – Pull needle roller 6, inner rotor 7 and outer rotor 8 out of the oil pump casing.
4-7C Dismounting the upper cylinder-head portion – Loosen each of the 6 bolts together with their sealing rings and dismount both valve covers 1 together with their gaskets. – Unscrew the spark plug. 1 – Unfasten 4 bolts and dismount the water pump cover 2 together with its gasket. 2 – Loosen all bolts 3 of the upper cylinder head part. 3 3 3 3 3 – Use a plastic hammer to carefully tap upwards in area A and lift off the upper cylinder head part.
4-8C – Apply the timing chain separating tool and open the timing chain by turning the spindle (see photo). ! CAUTION ! – MAKE SURE THAT THE PUSHED-OUT BOLTS DO NOT FALL INTO THE ENGINE. – PREVENT THE TIMING CHAIN FROM FALLING INTO THE CHAIN TUNNEL. – THE OPENED RIVET LINK IS TO BE DISCARDED. NOTE: Every rivet link of the timing chain can be opened. – To keep the timing chain from falling into the chain tunnel, you should insert a cable tie through the ends of the timing chain.
4-9C – Remove the wire circlip and the push piston bolt from the piston. Dismount the piston. Dismounting timing chain and timing gear – Loosen the 2 bolts 1 and dismount the fall-out protection element 2. – Remove the timing chain. 1 1 2 – Remove the bolts 3 and 4. Pull timing chain tensioner and timing chain guide upward out of the engine casing. 4 3 – Remove circlip 5. 5 – Apply the puller tool and pull the timing gear off the crankshaft.
4-10C 2 Dismounting E-starter drive gear and kickstarter 1 – Remove the 2 circlips 1 and the stop discs. Pull the kickstarter idler gear 2 and the E-starter idler gear 3 off the bearing bolts. 3 1 – Pull the reduction gear and the needle bearing off the bearing bolt. Take the bearing bolt out of the engine casing. – Carefully loosen the collar bolt 4 while holding down the kickstarter spring. Release the kickstarter spring and unhitch the spring shackle. Art.-No.
4-11C Dismounting primary gear and free wheel – Remove the collar nut 1. 1 ! CAUTION ! COLLAR NUTS WITH LEFT-HAND THREAD AND WITH RIGHT-HAND THREAD WERE USED RESPECTIVELY. COLLAR NUTS LABELED AS "LEFT" HAVE A LEFT-HAND THREAD. COLLAR NUTS WITHOUT LABELING HAVE A RIGHT-HAND THREAD. 2 NOTE: The collar nut 1 was already removed from the 250 EXC models from 2002 and the 450/525 models from 2003 as described on page 4-5. – Loosen the 2 bolts 2 and dismount the oil pump cover.
4-12C Dismounting shift mechanism and transmission – Turn the engine sideward. – Unfasten the engine fixture at the engine work stand – Applying a suitable tool to the cast-on members on the casing, lift off the left half of the casing, or separate it from the right half by slightly tapping on the countershaft with a plastic hammer. ! CAUTION ! TRY TO AVOID PRYING THE HALVES APART WITH A SCREWDRIVER OR A SIMILAR TOOL AS THIS IS APT TO INFLICT DAMAGE ON THE SEALING SURFACES.
4-13C Dismounting balancer shaft and crankshaft – Turn the crankshaft until the marks on the balancer shaft and crankshaft match. – In this position, the balancer shaft can be pulled out of the bearing seat. – Pull the crankshaft out of the bearing seat. – Clean all components, check them for wear and, if necessary, replace them with new ones. NOTE: For a complete engine overhaul procedure, we recommend that you replace all gaskets, shaft seal rings, O-rings, and bearings.
5-1C SERVICING INDIVIDUAL COMPONENTS Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No. 3206007 -E INDEX LEFT CASING HALF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-2 RIGHT CASING HALF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-3 CLUTCH COVER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-5 CRANKSHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IMPORTANT NOTE REGARDS WORKING ON ENGINE HOUSING Read through the following section before commencing work. Then determine the assembly sequence so that the engine housing halves only need to be heated up once before replacing the bearings. Having first removed the dowels, in order to expel the bearings or remove them with light mallet blows, the housing halves must be placed on a suitably large plane surface, supporting the whole of the sealing surface without damaging it.
5-2C 3 6 2 Left casing half Remove all shaft seal rings and use an oven to heat the casing half to approx. 150°C. Cylindrical roller bearing of crankshaft 1 Use a suitable punch to press the cylindrical roller bearing from the outside to the inside. From the inside, press in a new cylindrical roller bearing up to the stop. 8 1 7 Grooved ball bearing of main shaft 2 Use a suitable punch to press the grooved ball bearing from the outside to the inside.
5-3C The oil pump housing must not have any score marks or seizing marks. Blow compressed air through all oil ducts and check them for unobstructed passage. Check the 2 dowels 1 for tight fit and, if necessary, adhere them by means of Loctite 243. 1 Right casing half 3 4 Remove all shaft seal rings and use an oven to heat the casing half to approx. 150°C. Cylindrical-roller bearing of crankshaft 2 Use a suitable punch to press the cylindrical-roller bearing from the outside to the inside.
5-4C Grooved ball bearing 1 and seal ring 2 of balancer shaft. Use a bearing extractor to pull the grooved ball bearing out of the casing half and remove the seal ring. Press a new shaft seal ring in to a flush position, its open side facing downward. Press new grooved ball bearing in up to the stop. 2 1 1 4 Grooved ball bearing of shift roller 3 Remove the screw A. At a casing temperature of approx. 150°C, the grooved ball bearing will fall out from the bearing seat almost by itself.
5-5C Oil jet "100" 1 Dismount the oil jet and clean with compressed air. Degrease the thread of the oil jet, apply Loctite 243 and mount the oil jet. NOTE: This jet is used to dose the amount of oil for the conrod bearing. 1 Bypass valve Check valve plunger, sealing seat, and pressure spring for damage. Minimum length of pressure spring 2: 23.5 mm 2 NOTE: If the length of the pressure spring is less than 23.5 mm, the opening pressure of the bypass valve will decrease.
5-6C A B Crankshaft Art.-No. 3206007 -E If the conrod bearing is replaced, take care to properly position the crankpin. The bores of the crank web A and crank pin B must coincide. ! CAUTION ! IF THE CRANK PIN IS PRESSED IN THE WRONG POSITION, THE CONROD BEARING IS SUPPLIED INSUFFICIENTLY OR NOT AT ALL WITH ENGINE OIL, WHICH RESULTS IN BEARING DAMAGE. Repair manual KTM 250-525 SX, MXC, EXC RACING If the crankshaft will continue to be used, check crankshaft journals for run out.
5-7C Crankshaft webs – measure outer dimension Crankshaft webs – measure outer dimension with a sliding caliper as illustrated. Crankshaft webs – outer dimension = 65 mm ± 0.05 mm Driving gear of balancer shaft – Before pulling the driving gear off the balancer shaft you have to remove the inner ring of the crankshaft bearing: – For this purpose, secure the crankshaft with the crankshaft web carrying the inner ring to be replaced in a vise. – Heat the special tool 584.29.037.
5-8C Cylinder – Nikasil coating Nikasil is the brand name for a cylinder coating process, developed by the piston manufacturer Mahle. The name is derived from the two materials used in this process - a nickel layer into which the particularly hard silicon carbide is embedded. The main advantages of the Nikasil coating are excellent heat dissipation and thus better power output, low wear and low weight of the cylinder.
5-9C Checking the piston – Replace the piston in the case of excessive oil consumption or grooves in the piston skirt. – If reinstalling the old piston perform the following steps: 1. Piston bearing surface - check for damage. 2. Piston ring grooves - the piston rings must move easily in the groove. Old piston rings or sandpaper (400 grit) may be used to clean the piston ring grooves. 3. Piston rings - check for damage and end gap (see below).
5-10C 2 2 5 1 7 3 8 4 6 Art.-No. 3206007 -E 7 7 7 6 8 7 7 3 Repair manual KTM 250-525 SX, MXC, EXC RACING Lubrication system Oil line 1 Check for hairline cracking at the soldering joints, blow compressed air through the oil line and, while doing that, check it for unobstructed passage. In addition, check the oil line for possible scuff marks and replace the copper seal rings (8x12x1) O-rings 2 Replace the O-rings during every oil filter change.
5-11C 10 4 10 6 4 5 2 11 3 1 7 7 9 9 8 Upper portion of cylinder head – Remove circlip 1 and pull the decompressor shaft 2 together with spring 3 out of the bore. – Pull the two end pieces 4 together with the rocker arm pins 5 + 6 out of the cylinder head's upper portion. Withdraw the rocker arms 7. – Clean all components and check them for wear. Rocker arm pins 5 + 6 The rocker arm pins must not have any score marks and turning them in the rocker arms 7 must be easy.
5-12C Model 2003 250/450, 525 SX Art.-No. 3206007 -E Model 2003 250/450, 525 SX 2 1 Cylinder head Repair manual KTM 250-525 SX, MXC, EXC RACING – Loosen the 3 bolts 1 and dismount the exhaust flange 2 together with its gasket. – Dismount the 4 valves with the aid of a special tool. NOTE: – Conical springs are mounted on the 250 EXC and 450/525 SX models from 2003. – When being mounted again, used valves must be mounted in the same valve guide as before.
5-13C – Take the valve spring retainer 1 and the valve springs 2 out of the cylinder head. – Pull the valve stem gaskets off the valve guides and remove the spring seats 3. NOTE: Conical springs are mounted on the 250 EXC and 450/525 SX models from 2003. 1 3 2 Sealing surface Check the spark plug thread and the valve seats for damage and cracks. Use a ruler and a feeler gauge to check the sealing surface of the cylinder head for distortion. Max. distortion: 0.10 mm (0.0039 in).
5-14C 12 10 11 8 6 5 9 7 4 8 2 3 1 Camshaft Art.-No. 3206007 -E – Dismount circlip 1 and water pump wheel 2. – Pull the needle roller 3 out of the hole in the camshaft and pull the gasket carrier 4 off of the camshaft. – Use the puller tool to extract the grooved ball bearing 5 from the camshaft (see photo). ! Repair manual KTM 250-525 SX, MXC, EXC RACING NEVER CAUTION ! CLAMP THE CAMS OF THE CAMSHAFT INTO A VISE.
5-15C – Press the shaft seal rings 1 out of the gasket carrier 2. – Press the new shaft seal rings in up to a flush position, with the open side facing outwards. Thoroughly grease the sealing lips. 1 4 – Take the 2 O-rings 3 off the gasket carrier and remove the gasket residues with a wire brush. – Mount 2 new O-rings. NOTE: – The two O-rings 3 have different sizes starting with the 2002 model. The smaller O-ring is mounted on the outside, i.e. facing the water pump wheel.
5-16C Timing chain tensioner – Pull the pressure pin of the timing chain tensioner out all the way and check whether or not it moves smoothly. – Check the toothing on the pressure pin and the ratcheting pawl for wear. – For mounting, push the ratchet in the direction of the arrow so that the pressure pin will no longer be locked and push the pressure pin all the way into the tensioner housing. Timing train Art.-No. 3206007 -E Clean all components thoroughly and check them for wear.
5-17C Modification - Model 2001 4 3 15 10 14 5 8 1 B Modification - Model 2002 C 11 A 13 2 4 12 7 6 7 Checking the clutch for wear Thrust bearing 1 Check it for seizing marks and unobstructed movability. Push rod 2 Place it on a planar surface and check it for eccentricity. Modification - Model 2002 9 Clutch springs 3 Minimum length: 42 mm (1.6535 in) - new: 43 mm (1.6929 in); if necessary, replace all 6 springs. 8 7 lining discs 4 Minimum thickness: 1.7 mm (0.0669 in) - new: 1.8 mm (0.
5-18C Modell 2003 5 LOCTITE 243 4 9 7 6 1 A 2 LOCTITE 243 7 8 B 10 3 Art.-No. 3206007 -E 11 Checking the clutch for wear Pressure piece 1 Check it for seizing marks and unobstructed movability. Axial needle bearing 2 Check for damage. Repair manual KTM 250-525 SX, MXC, EXC RACING Push rod 3 Place it on a planar surface and check it for eccentricity. Clutch springs 4 Minimum length: 42 mm (1.6535 in) - new: 43 mm (1.6929 in); if necessary, replace all 6 springs.
5-19C 3 11 10 12 9 8 7 1 2 6 5 4 Checking the kickstarter for wear Take all components off the kickstarter shaft and clean them. Kickstarter gear 1 Check the toothing for wear and the bearing for clearance. Kickstarter idler gear 2 Check the bearing for clearance and seizing marks. Check the toothing for wear. It is constantly engaged with the outer clutch hub. Kickstarter ratchet gear 3 Check the inclined surface and the toothings for wear.
Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No.
5-21C Shift mechanism Shift forks 1 Check plate A for wear. The forks are 4.8mm - 4.9 mm (0.1889 in 0.1929 in) thick in a new condition. The wear limit is at 4.6 mm (0.1811 in). Shift roller 2 Check the shift grooves B for wear. Check the fit of the shift roller in the grooved ball bearing 3. Grooved ball bearing 3 Check it for smooth movability. Shift rolls 4 Check the shift rolls for pressure marks and cracks. Shift rails 5 Check the shift rails for eccentricity on a planar surface.
5-22C 1 2 3 4 Art.-No. 3206007 -E 5 Transmission Clamp the main shaft or counter shaft, respectively, into the vise (use protective jaws).
5-23C 1 2 3 4 5 6 7 8 9 10 11 Transmission Clamp the main shaft or counter shaft, respectively, into the vise (use protective jaws).
5-24C 17 18 16 15 14 13 12 11 10 9 7 8 6 5 4 3 Art.-No. 3206007 -E 2 1 Repair manual KTM 250-525 SX, MXC, EXC RACING Transmission Clamp the main shaft or countershaft, respectively, into the vise (use protective jaws).
5-25C Ignition General information The measurements described below will only reveal severe problems. Coil short circuits leading to weak ignition sparks or low generator output, respectively, can only be detected with the help of an ignition test bench. In the case of malfunction always check the cables and the plug and socket connections of the ignition system first. Make sure to select the correct measuring range when performing measurements. The CDI unit can only be checked on the ignition test bench.
5-26C 7 6 1 2 3 5 A Art.-No. 3206007 -E 4 E-starter drive gear Idler gear 1 Check toothing and bearing position of the idler gear for wear. Check the bearing bolts of the idler gear for score marks, as well. Repair manual KTM 250-525 SX, MXC, EXC RACING Reduction gear 2 Check toothing and bearing position of the idler gear for wear. Check the bearing bolts of the idler gear for score marks, as well. Slip the reduction gear together with the needle cage onto the bearing bolt and check the clearance.
5-27C Checking the free wheel – Insert the free wheel gear 1 into the free wheel 2. – It must be possible to turn the free wheel gear clockwise. – Counterclockwise, the free wheel gear must be blocked without backlash. 1 2 Replacing the free wheel hub 3 2 – Use the circlip pliers to compress the spreader ring 3 and remove it together with the free wheel 2. A 4 – Remove the 6 bolts 4. – Use a plastic hammer to tap on the free wheel hub 5 from the side and dismount the free wheel hub.
6-1C ASSEMBLING THE ENGINE Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No. 3206007 -E INDEX MOUNTING THE CRANKSHAFT AND BALANCER SHAFT . . . . . . . . . . . . .6-2 MOUNTING THE SHIFT MECHANSIM AND TRANSMISSION . . . . . . . . . . .6-2 ASSEMBLING THE ENGINE CASE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-4 MOUNTING THE PRIMARY GEAR AND FREE WHEEL . . . . . . . . . . . . . . . .6-4 MOUNTING THE OIL PUMPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-2C Mounting the crankshaft and balancer shaft – Secure the right half of the casing in the work stand. – Thoroughly oil the cylinder roller bearings of the crankshaft and grease the shaft seal ring of the crankshaft. – Carefully, insert the crankshaft into the bearing seat. – Turn the crankshaft such that the mark A is in front and insert the balancer shaft into the bearing seat. Make sure that the mark A on the crankshaft is between the 2 marks B on the balancer shaft.
6-3C – Oil the shift forks at their flat sides and engage them in the sliding gears. ONLY ENGINES WITH 4-SPEED-SHIFTING: NOTE: The shift fork 1 and the short shift rail is not mounted in these engines. 1 – Insert shift roller into bearing seat. ONLY ENGINES WITH 4-SPEED-SHIFTING: A NOTE: The shift roller must be turned with the shift roller mounted such that the pin A faces vertically downward. – Engage the shift forks in the shift roller and mount the two shift rails 2 together with the springs.
6-4C 30 M6x... 30 45 45 60 45 75 60 45 45 45 60 60 Assembling the engine casing Art.-No. 3206007 -E – Remove the engine fixture at the work stand. – Slightly coat the casing sealing surface with grease and apply a new gasket to it. – Put on the left half of the casing and tap on it lightly with a plastic hammer until it reaches its proper fit. – Check the casing gasket for proper fit. – Grease the casing bolts in the area of their threads and at the seating surfaces of their heads.
6-5C Mounting the oil pumps – Thoroughly clean the seating surface of the oil pump cover. – Insert the needle roller into the oil pump shaft. – Slide inner rotor and outer rotor onto the oil pump shaft such that the 2 center points A and B are located next to one another and insert all components into the engine casing. A NOTE: The inner and outer rotor must be mounted with the center points facing the casing. B – Fill the oil pump casing with engine oil.
6-6C Mounting the shift arrester – Slip the disc 2, the locking lever 3, the locking spring sleeve 4 and the locking lever spring 5 onto the bolt 1 (M5x20). – Apply Loctite 243 to the bolt's thread and tighten the bolt to 6 Nm/5 ft.lb. 1 1 3 2 4 5 – Slide the shift locating drum 6 onto the shift roller. Please note that the flat portions are eccentric. Here, the locking lever has be drawn away from the shift roller.
6-7C – Insert the bearing bolt into the casing bore. Mount the needle bearing 1 and the reduction gear 2. 1 2 – Insert the preassembled kickstarter shaft into the bearing bore such that the ratchet gear is positioned behind the release plate. 3 – Mount the spring shackle to the starter spring, coat the thread of the bolt 3 (M6x12) with Loctite 243, tighten to 10 Nm/7 ft.lb, preload the starter spring around approx. 45° clockwise and fix the spring shackle by means of the bolt.
6-8C Mounting the outer clutch hub and driver from the 2003 model onwards – Mount the supporting plate and the oiled needle bearing 1. – Mount the outer clutch hub 2 together with the half disks 3 and stepped disk 4 on the main shaft. 2 3 4 1 – – – – Heat the driver to approx. 150°C and mount on the main shaft. Mount a new lock washer. Degrease the main shaft thread and apply Loctite 243. Apply the special tool (see dismounting), mount the collar nut 5 and tighten to 150 Nm.
6-9C Mounting the timing gear – Check the Woodruff key in the crankshaft for its correct fit. – Warm the timing gear 1 and position on the crankshaft with the high collar facing inwards. Tap carefully with a suitable pipe if necessary. – Mount circlip 2 with the sharp edge facing outwards. 1 2 – Degrease the threads of the 2 bolts and apply Loctite 243. Use the 2 bolts 5 (M6x25) to fix the timing chain guide 3 and the tensioning rail 4 , tighten the bolts to 8 Nm/6 ft.lb. Do not forget the 2 bushings.
6-10C Mounting piston and cylinder – Apply a new cylinder-base gasket. – Oil the piston pin boss in the conrod and the piston pin. – Mount the piston and secure the piston pin with 2 new wire circlips. ! THE CAUTION ! ARROW AT THE PISTON HEAD MUST POINT IN THE TRAVEL DIRECTION. – Oil the piston and align the piston rings. NOTE: The open end of the oil scraper ring must be in the back. The open end of the compression ring must be offset from it around 90°.
6-11C NOTE: The gasket carrier has a drain bore A from the 2003 model. Make sure the bore faces up when mounting. A B – Place the camshaft into the cylinder head such that the marks B at the camshaft gear are aligned with the upper edge of the cylinder head (see photo). The stop bolt of the automatic decompressor must be on top. NOTE: When mounting the camshaft, you have to use the crankshaft fixing bolt to block the crankshaft in the TDC position.
6-12C Mounting cylinder head top portion – – – – Clean and degrease the sealing surface. Fit dowels. Apply a thin layer of sealing compound (Three Bond). Carefully position cylinder head top section and tighten bolts to 10 Nm/7 ft.lb. NOTE: – The bolt M6x75 is to be mounted with a new copper seal ring (6x10x1) M6x... 55 55 45 30 75 30 45 50 – Prior to fastening the bolts, it is necessary to check and, if necessary, adjust the clearance play of the rocker arms.
6-13C Mounting the timing chain tensioner – Mount the preassembled timing chain tensioner 1 with a new gasket. – Mount the 2 bolts (M6x20) with copper seal rings 6x10x1 and tighten to 8 Nm/6 ft.lb. 1 – Use a screwdriver to push the pressure pin in until you feel a slight resistance. Then, push it in one notch further. – Mount the pressure spring and the plug with a new sealing ring and tighten to 10 Nm/7 ft.lb.
6-14C Mounting the flywheel (400/520 models up to 2002) – Check the Woodruff key in the crankshaft for proper fit and slip the flywheel onto the crankshaft. – Mount wave washer and collar nut, tighten to 60 Nm/44 ft.lb. NOTE: When ordering a new part, a forged rotor will be supplied, this part is produced without rivets and is interchangeable. – Unscrew the crankshaft fixing bolt, mount the sealing ring 1 and tighten the crankshaft fixing bolt again to 25 Nm/18 ft.lb.
6-15C Mounting the clutch 2 – Prior to assembly, thoroughly oil all lining discs. Clutch disks up to the 2001 model: – Starting with an intermediate disc 1, alternatingly insert a total of 8 intermediate discs and 7 lining discs 2. An intermediate disc must be on top. 1 5 3 4 6 Clutch disks from the 2002 model onwards: – Position the 12 driving pin sleeves 3 on the driver; fix with grease if necessary.
6-16C Mounting the oil line – Position the oil line 3 and secure it with the jet screw 1 and the hollow screw 2. Use new sealing rings, tighten the screws to 10 Nm/8 ft.lb. 1 2 NOTE: Place the oil line such that it does not touch the engine. The oil line must not be twisted during tightening. 3 Mounting the electric starter Art.-No. 3206007 -E – Oil the O-ring of the E-starter motor and insert the E-starter motor into the engine casing. Mount the 2 screws 4 (M6x20) and tighten to 8 Nm/6 ft.lb.
6-17C Mounting the oil filters – Fill the oil filter housing with engine oil to approx. 1/4 of its capacity. – Insert both oil filters 1 into the engine casing. 1 – Oil the O-rings at the oil filter cover and secure the oil filter cover 2 by means of the 4 bolts (M5x16), tighten to 6 Nm/5 ft.lb.. 2 – Mount kickstart and shift lever. How to fill in engine oil – Mount the plugs 3 and 4 and the oil drain plug 5 and tighten them. 4 NOTE: Tightening torque 3 10 Nm/0.4 ft.lb, 4 15 Nm/0.6 ft.
7-1C ELECTRICAL SYSTEM Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No. 3206007 -E INDEX LEAKAGE INSPECTION . . . . . . . . . . . . . . . . . . . . . REMOVING THE BATTERY . . . . . . . . . . . . . . . . . . CHARGING THE BATTERY . . . . . . . . . . . . . . . . . . FILLING THE BATTERY . . . . . . . . . . . . . . . . . . . . . CHECKING THE CAPACITOR . . . . . . . . . . . . . . . . CHECKING THE VOLTAGE REGULATOR-RECTIFIER CHECKING THE CHARGING VOLTAGE . . . . . . . . . CDI UNIT . . . . . . . . . . .
7-2C Leakage inspection The drop test must be performed before checking the voltage regulator/rectifier – Turn off the ignition and disconnect the ground wire from the battery. – Insert an amperemeter between the ground wire and the negative pole of the battery. Setpoint value: max. 1 mA – Check for power consumers, should the measured value exceed the indicated maximum value.
7-3C Filling the battery – Take the battery and the electrolyte container out of the packaging. Before you start filling the battery, please read the enclosed instructions carefully. – Take the cover off the electrolyte container. – Apply the electrolyte container to the filling apertures of the battery and push it down tight. – Once all chambers of the electrolyte container are empty, withdraw it from the battery. – Close the filling apertures tightly by means of the cover.
7-4C Checking the voltage regulator-rectifier A defect voltage regulator can cause different kinds of trouble: ● No voltage in the circuit In this case, the voltage regulator must be disconnected at idle speed. The voltage regulator is defect if the power consumers now work properly. If the power consumers are still not supplied with power, the switch, the wiring harness or the ignition system must be checked for defects. ● Excessive voltage in the circuit The bulbs burn out.
7-5C CDI unit Check the cables and plug and socket connections of the CDI unit. The CDI unit function can only be checked on an ignition test bench. ! CAUTION NEVER USE A COMMERCIAL MEASURING DEVICE COMMERCIAL MEASURING DEVICES CAN DESTROY COMPONENTS. ! TO CHECK THE CDI UNIT. HIGHLY SENSITIVE ELECTRONIC Ignition coil – Disconnect all cables and remove the spark plug connector. – Use an ohmmeter to measure the following values. NOTE: The indicated setpoint values correspond to a temperature of 20° C.
7-6C Main fuse NOTE: The fuse 1 is positioned in the starter relay of the E-starter underneath the left side paneling. The following loads are connected to it: – E-starter system – horn – flasher lights The fuse 2 serves as a spare fuse. – To replace it, remove the left trim panel and pull the cover off the start relay. – Pull out the fuse and replace it with a new one. ! CAUTION ! NEVER INSERT A STRONGER FUSE OR "MEND" THE FUSE.
7-7C STATIC IGNITION VALUES 250-525 SX, MXC, EXC RACING (KOKUSAN 4K-3A, B) Measuring conditions: – cold engine – seat and tank removed – all connectors and the ground connection in a non-corroding condition, connectors tightly connected – battery loaded (if installed) and light switch turned off – the gap between the rotor and pulse generator must be set to 0.
Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No.
7-9C STATIC GENERATOR VALUES 250-525 MXC, EXC RACING (KOKUSAN 4K-3B) Measuring conditions: – cold engine – seat and tank removed – all connectors and the ground connection in a non-corroding condition, connectors tightly connected – battery loaded (if installed) and light switch turned off – compression release lever pulled – kick the kick starter forcefully at least 5 times for each measurement Check the generator output 6 (also see circuit diagram on opposite page) for voltage between the following cable
Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No.
7-11C DYNAMIC GENERATOR VALUES 250-525 MXC, EXC RACING (KOKUSAN 4K-3B) Measuring conditions: – remove seat, side trim and left side cover – all connectors and the ground connection in a non-corroding condition, connectors tightly connected – battery in a startable condition, not fully loaded (start several times for fully loaded battery) – start engine, the measurement must be taken right after starting Regulator rectifier output – measure the voltage with the measuring leads of the peak voltage adapter di
8-1C 8 FUEL SYSTEM Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No. 3206007 -E INDEX DISMOUNTING AND INSTALLING THE CARBURETOR . . . . . . . . . DISASSEMBLING THE CARBURETOR (KEIHIN FCR 35/39) . . . . . . DISASSEMBLING THE CARBURETOR (KEIHIN FCR-MX 37/39/41) . CHOKE SLIDE AND HOT START KNOB . . . . . . . . . . . . . . . . . . . . CHECKING THE ACCELERATOR PUMP . . . . . . . . . . . . . . . . . . . . CHECKING THE JET NEEDLE . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8-2C Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No. 3206007 -E CARBURETOR - KEIHIN FCR 35 / 39 NOTE: the Keihin FCR 39 carburetor (400/520 Racing) has a larger air trumpet and a different carburetor jets than the Keihin 35 carburetor (250 Racing). The FCR 39 carburetor is also equipped with a throttle sensor.
8-3C CARBURETOR - KEIHIN FCR-MX 37 / 39 / 41
8-4C Dismounting and installing the carburetor NOTE: Before you start working on the carburetor, you should clean the motorcycle thoroughly. 1 – Dismount the seat and the tank with spoilers. – Unfasten the 2 bolts 1 and remove the cover. 1 – Unfasten the 2 nuts 2 and unhitch both throttle cables at the carburetor. 2 – Loosen the plug at the float chamber and drain the fuel into a suitable receptacle. Then, retighten the plug. – Disconnect the plug-and-socket connection of the throttle valve sensor.
8-5C Disassembling the carburetor FCR 35/39 NOTE: Before you start disassembling the carburetor, you should look for a clean workplace. It should offer you enough space to lay out all individual components of the carburetor in perfect order. – Dismount the carburetor and remove any coarse dirt. 1 – Remove the wire clip 1 and pull the ventilation hoses out of the carburetor. – Disconnect the hose 2. – Loosen the 2 bolts 3 and dismount all ventilation hoses from the carburetor.
8-6C – Now, pull the cable disc approx. 5 mm (0.1968 in) outward and turn it until the throttle valve can be lifted out of the carburetor and detach the rollers 1 at the throttle valve. – Take the throttle valve together with the 4 rollers 2 and the valve paddle out of the carburetor. 2 NOTE: When you turn the cable disc, it must not be blocked by the stop screw (see photo). Otherwise, pull the shaft further outward.
8-7C – Remove the screw 1 and dismount the throttle-valve sensor 2. When unfastening the screw, be sure to watch out for the bushing 3. 4 3 NOTE: To dismount the throttle-valve sensor, always remove the screw 1. After the screws 4 were loosened, the throttle-valve sensor must be adjusted again. 1 2 4 – Remove the screw and the clip together with the bushing and pull the connection piece 5 out of the carburetor.
8-8C Disassembling the carburetor Keihin FCR - MX 37/39/41 NOTE: Before you start disassembling the carburetor, you should look for a clean workplace. It should offer you enough space to lay out all individual components of the carburetor in perfect order. – Dismount the carburetor and remove any coarse dirt. – Loosen both screws 1 and remove all of the vent hoses from the carburetor. 1 1 – Remove both screws 2 and remove the slide cover and gasket from the carburetor.
8-9C – Turn the carburetor around, remove the 3 screws and remove the cover of the accelerator pump. NOTE: When dismounting the cover, watch out for the spring and the sealing rings as they may get lost easily. – Remove the 2 sealing rings, the spring and the diaphragm from the pump housing. – Remove the screws on the float chamber and remove the housing. 2 – Pull out the float hinge pin 1 and remove the float together with the float needle valve. – Remove the main jet 2.
8-10C – Remove screws 1 and the throttle sensor 2. 2 1 NOTE: the throttle sensor should only be dismounted if defective. If the screws 1 are loosened, the throttle sensor must be adjusted again. 1 – Remove screw 3 and pull the connecting piece out of the carburetor. 3 Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No. 3206007 -E 4 5 6 – Remove the 2 screws and take the intake trumpet together with the O-ring 4 off the carburetor. – Unscrew the idle-air jet 5 and the main air jet 6.
8-11C Checking the choke slide and hot start knob Choke slide: The choke slide must be easy to actuate . The piston 1 of the choke slide must not have any pronounced score marks or deposits. 1 Hot start knob: The hot start knob must be easily actuated. The piston on the hot start knob may not have any scores or deposits. Checking the accelerator pump Check the membranes for cracking or brittleness. Check gaskets for damage. Check if the bores 2 are unobstructed.
8-12C Assembling the carburetor FCR 35/39 – Mount the idle-air jet 1 and the main air jet 2. – Place the O-ring 3 in the groove and secure the intake trumpet to the carburetor by means of the 2 screws. 3 2 1 – Insert the fuel connection 4 into the carburetor and secure it with the clip. NOTE: In the mounted state, the connection piece must be easy to turn. 4 – Mount the choke slide 5 and actuate it several times, checking whether it can be moved smoothly.
8-13C – Position the float, mount the float hinge pin and secure it by means of the screw. – Check the float level (see page 8-13). – Stick the plastic component 1 on the needle jet. 1 – Engage the push rod 2 of the accelerator pump at the lever. 2 – Mount the float chamber and at first secure it with only 1 screw. When positioning the float chamber, make sure that the push rod 2 of the accelerator pump slides into the bore.
8-14C – Coat the thread of the screw 1 with Loctite 243 and mount the screw, however, do not tighten it yet. – Push the slide pin 2 inward. At the same time, push the slide lever 3 to the extreme right and tighten the screw 1. 2 1 3 – Now, the distances A on the left and on the right should be identical. Then, turn the cable disc and check if the throttle valve moves smoothly. – Mount the jet needle and secure it with the screw 4. – Position the slide cover and gasket and fasten with 2 screws.
8-15C Assembling the carburetor Keihin FCR - MX 37/39/41 3 1 – Mount the idle-air jet 1 and the main air jet 2. – Place the O-ring 3 in the groove and secure the intake trumpet to the carburetor by means of the 2 screws. 2 – Insert the fuel port in the carburetor and fix with screw 4. NOTE: In the mounted state, the connection piece must be easy to turn. 4 – Mount the choke slide 5, the hot start knob 6 and actuate several times, checking for smooth operation.
8-16C – Position the float and the float needle valve and mount the float hinge pin 1. – Check the float level (see page 8-21). 1 – Mount the float chamber and the gasket, position the bracket for the adjustment screw 2 and fix the float chamber with the screws 3. NOTE: When positioning the float chamber, make sure that the push rod 4 of the accelerator pump slides into the bore. 2 3 4 – Place the membrane 5 with the labeling facing upwards and the spring into the pump housing.
8-17C – Apply Loctite 243 to the screw 1 and tighten. – Mount the jet needle and fix with the screw 2. 2 1 – Position the slide cover with the gasket and fasten with the 2 screws 3. 3 3 – Fix the vent hoses on the float chamber with the 2 screws 4.
8-18C Adjusting the position of the throttle valve sensor 2 1 NOTE: Before checking the position of the throttle valve sensor, you have to adjust the idle speed correctly. – Disengage the plug-and-socket connection of the throttle valve sensor. – Connect a multimeter (measuring range Ω x 1k) to the blue (+) and the black (-) cable of the throttle valve sensor and measure the throttle valve resistance. – Now, multiply this value by 0.15. This yields the adjustment value for the throttle valve sensor.
8-19C Checking the throttle valve sensor NOTE: The following measurement must be taken at a component temperature of approx. 20°C. – Open the plug-and-socket connection of the throttle valve sensor. – Connect a multimeter (measuring range Ω x 1k) to the blue (+) and the black (-) cable of the throttle valve sensor. Resistance of throttle valve sensor: 4 - 6 kΩ bl bl – Now, connect the multimeter to the yellow (+) and the black (-) cable of the throttle valve sensor.
8-20C CARBURETOR – Adjust idling FCR 35/39 Idling adjustment of the carburetor strongly affects the engine’s starting behavior. An engine whose idling speed is adjusted correctly will be easier to start than one whose idling speed has not been adjusted correctly. 1 The idle speed is controlled by means of the adjusting wheel 1 and the mixture control screw 2. The adjusting wheel is used to adjust the basic setting of the slide.
8-21C CARBURETOR – Adjust idling (Keihin-FCRMX 37/39/41) Idling adjustment of the carburetor strongly affects the engine’s starting behavior. That is, an engine whose idling speed is adjusted correctly will be easier to start than one whose idling speed has not been adjusted correctly. The idle speed is controlled by means of the adjusting wheel 1 and the mixture control screw 2. The adjusting wheel is used to adjust the basic setting of the slide.
9-1C TECHNICAL SPECIFICATIONS Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No. 3206007 -E INDEX MODEL 2000 TECHNICAL SPECIFICATIONS - ENGINE . . . . . . BASIC CARBURETOR SETTING . . . . . . . . . . . . . TIGHTENING TORQUES - ENGINE . . . . . . . . . . ASSEMBLY CLEARANCE, WEAR LIMIT . . . . . . . TECHNICAL SPECIFICATIONS - CHASSIS . . . . . . STANDARD ADJUSTMENT - FORK . . . . . . . . . . STANDARD ADJUSTMENT - SHOCK ABSORBER TIGHTENING TORQUES - CHASSIS . . . . . . . . . . . . . . . . . . . . .
9-2C Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No.
9-3C TIGHTENING TORQUES - ENGINE Hexagon collar screw engine case, clutch cover, ignition cover Oil drain plug Allan head plug oil screen short Hexagon plug oil screen long Plug pressure valve Jet screw and hollow screw oil line Screws oil pump cover Hex.
9-4C ASSEMBLY CLEARANCE, WEAR LIMIT Crankshaft Conrod bearing Cylinder 400 Cylinder 520 Piston forged Piston cast Piston ring end gap Valves Oil pumps Bypaß valve Clutch Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No. 3206007 -E Transmission shafts axial play . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.03 - 0.15 mm run out of crank stud . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .max. 0.08 mm radial play . . . . . . . . . . . . . . . .
9-5C TECHNICAL DATA – CHASSIS 400 SX RACING 400/520 SX, EXC RACING 2000 520 SX RACING Frame 400/520 EXC RACING 400/520 EXC RACING USA Central chrom-moly-steel frame Fork White Power – Up Side Down 43 MA Wheel travel front/rear 295/320 mm Rear suspension WP Progressive Damping System shock absorber, aluminium swingarm Front brake Disc brake with carbon-steel brake disc Ø 260 mm (10.2 in), brake caliper floated Rear brake Disc brake with carbon-steel brake disc Ø 220 mm (8.
9-6C Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No.
9-7C TECHNICAL DATA – CHASSIS 400/520 SX, MXC, EXC RACING 2001 400 SX RACING Frame Fork Wheel travel front/rear Rear suspension Front brake Rear brake Brake disc Front tires Air pressure offroad Air pressure road driver only Rear tires Air pressure offroad Air pressure road driver only Fuel tank capacity Final drive ratio Chain Available final sprockets Steering head angle Wheel base Seat height, unloaded Ground clearance, unloaded Dead-weight * 520 SX RACING 400/520 EXC RACING 400/520 EXC USA, MXC Cent
9-8C Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No.
9-9C BASIC CARBURATOR SETTING 250 EXC RACING 250 EXC RACING 8,3 kW 400 SX RACING 400 MXC/EXC RACING 400 EXC RACING 12 kW 520 EXC RACING 12,5 kW Keihin CR35 170401 160 OBEVP 48 200 100 6. th from top 85 1,25 15 – 0 Keihin CR35 041200 160 OBEVR 45 200 100 6. th from top 85 1,0 15 Slide stop 24,5 mm 0 Keihin CR39 031299 175 OBDTM 48 200 100 4. th from top 85 1 15 – 3,2 mm Keihin CR39 130799 175 48 200 100 3.
9-10C ASSEMBLY CLEARANCE, WEAR LIMIT UP TO THE 2002 MODEL Crankshaft axial clearance . . . . . . . . . . . . . . . . . . . . . . . .0.1 - 0.2 mm/0.0039 - 0.0078 in Conrod bearing radial clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .max. 0.05 mm/0.002 in run out of crank stud . . . . . . . . . . . . . . . . . . . . . . . . . .max. 0.08 mm/0.003 in axial clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .max. 1.10 mm/0.
9-11C TECHNICAL DATA – CHASSIS 250/400/520 SX, MXC, EXC RACING 2002 400/520 SX RACING Frame Fork Wheel travel front/rear Rear suspension Front brake Rear brake Brake disc Front tires Air pressure offroad Air pressure road driver only Rear tires Air pressure offroad Air pressure road driver only Fuel tank capacity Final drive ratio Chain Available final sprockets Bulbs Battery Steering head angle Wheel base Seat height, unloaded Ground clearance, unloaded Dead-weight * 250/400/520 EXC RACING 400/520 MX
9-12C Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No.
9-13C BASIC CARBURATOR SETTING Type Carburator-setting number Main jet Jet needle Idling jet Main air jet Idling air jet Needle position Starting jet Mixture control screw open Slide Performance restrictor Stop pump membrane Hot start device 250 EXC RACING Six Days 250 EXC RACING 11 kW 450 EXC RACING 12 kW 450 SX RACING Keihin FCR-MX 37 3700A 160 OBETP 42 200 100 3. rd from top 85 1,25 15 – 858 / 2,15 mm – Keihin FCR-MX 37 3700A 160 OBEKT 42 200 100 3.
9-14C Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No. 3206007 -E TIGHTENING TORQUES Hexagon collar screw, engine case, clutch cover, ignition cover Oil drain plug Allan head plug oil, screen short Hexagon plug, oil screen long Collar screw for oil filter cover Plug pressure valve Jet screw and hollow screw, oil line Screws, oil pump cover Hexagon collar screw, cylinder head top section Hex.
9-15C ASSEMBLY CLEARANCE, WEAR LIMIT FROM THE 2003 MODEL Crankshaft axial clearance . . . . . . . . . . . . . . . . . . . . . . . .0.1 - 0.2 mm/0.0039 - 0.0078 in Conrod bearing radial clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .max. 0.05 mm/0.002 in Cylinder 250 bore diameter size I . . . . . . . . . . . . . . .75.000 - 75.012 mm/2.9527 - 2.9532 in Cylinder 450 EXC/MXC bore diameter size I . . . . . . . . . . . . . . .89.000 - 89.012 mm/3.5039 - 3.
9-16C TECHNICAL DATA – CHASSIS 250/450/525 SX, MXC, EXC RACING 2003 450/525 SX RACING Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No.
10-1C PERIODIC MAINTENANCE SCHEDULE INDEX MODEL 2000 PERIODIC MAINTENANCE SCHEDULE . . . . . . . . . . . . . . . . . . . . . . . . . .10-2 MODEL 2001 PERIODIC MAINTENANCE SCHEDULE . . . . . . . . . . . . . . . . . . . . . . . . . .10-4 MODEL 2002 PERIODIC MAINTENANCE SCHEDULE . . . . . . . . . . . . . . . . . . . . . . . . . .10-6 Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No. 3206007 -E MODEL 2003 PERIODIC MAINTENANCE SCHEDULE . . . . . . . . . . . . . . . . . . . . . . . . . .
10-2C Clean short and long oil screen and magnet of the drain plug whenever you exchange the engine oil Change short and long oil filter unit Check oil line for leakage and proper installation Check valve clearance and adjust if necessary before each start Check engine oil level Change spark plug Drain and clean carburetor float bowl Check breather hoses of engine case, gas tank and carburetor for correct position without buckles Clean air filter and a
10-3C SUPPLEMENTARY MAINTENANCE INSTRUCTIONS FOR THE 400/520 RACING ENGINE MODEL 2000 (ADDITIONAL ORDER FOR KTM WORKSHOP) Hours 400 SX 400 MXC/EXC 520 SX 520 MXC/EXC 15 Small Maintenance Kit – Small Maintenance Kit – 30 Small Maintenance Kit Small Maintenance Kit Small Maintenance Kit Small Maintenance Kit 45 Large Maintenance Kit – Large Maintenance Kit – 60 Small Maintenance Kit Large Maintenance Kit Small Maintenance Kit Large Maintenance Kit 75 Small Maintenance Kit – Small M
10-4C PERIODIC MAINTENANCE SCHEDULE 2001 Repair manual KTM 250-525 SX, MXC, EXC RACING BRAKES CHASSIS WHEELS Art.-No.
10-5C IMPORTANT CHECKS AND MAINTENANCE TO BE CARRIED OUT BY THE Before each start ● ● ● ● ● Check oil level Check brake fluid level Check brake pads for wear Check lights for function Check horn for function Lubricate and adjust cables and nipples Bleed fork legs regularly Remove and clean fork dust bellows regularly Clean and lubricate chain, check tension and adjust if necessary Clean air filter and filter box Check tires for pressure and wear Check cooling fluid level Check fuel lines for leaks Dr
10-6C PERIODIC MAINTENANCE SCHEDULE 2002 Repair manual KTM 250-525 SX, MXC, EXC RACING BRAKES CHASSIS WHEELS Art.-No.
10-7C IMPORTANT CHECKS AND MAINTENANCE TO BE Check oil level Check brake fluid level Check brake pads for wear Check lights for function Check horn for function Lubricate and adjust cables and nipples Bleed fork legs regularly Remove and clean fork dust bellows regulary Clean and lubricate chain, check tension and adjust if necessary Clean air filter and filter box Check tires for pressure and wear Check cooling fluid level Check fuel lines for leaks Drain and clean float chamber Check all control eleme
10-8C PERIODIC MAINTENANCE SCHEDULE 2003 Repair manual KTM 250-525 SX, MXC, EXC RACING BRAKES CHASSIS WHEELS Art.-No. 3206007 -E ADD- ON PARTS CARBURETOR ENGINE A clean motorcycle can be checked more quickly which saves money! 250/450/525 SX/MXC/EXC RACING 1.
10-9C IMPORTANT CHECKS AND MAINTENANCE TO BE Check oil level Check brake fluid level Check brake pads for wear Check lights for function Check horn for function Lubricate and adjust cables and nipples Bleed fork legs regularly Remove and clean fork dust bellows regularly Clean and lubricate chain, check tension and adjust if necessary Clean air filter and filter box Check tires for pressure and wear Check cooling fluid level Check fuel lines for leaks Drain and clean float chamber Check all control elem
10-10C Repair manual KTM 250-525 SX, MXC, EXC RACING 90 hours 600 liter 120 hours 800 liter 135 hours 900 liter Check the clutch disks for wear Check the length of the clutch springs Check the cylinder and piston for wear Check the groove on the piston pin retainer for wear (visual check) Check the camshaft for wear (visual check) Replace the camshaft bearings Check the length of the valve springs Check the spring cap for wear Check the eccentricity of the valve disk Check the valve guides for wear Che
10-11C 120 hours 800 liter 180 hours 1200 liter 240 hours 1600 liter 270 hours 1800 liter Check the clutch disks for wear Check the length of the clutch springs Check the cylinder and piston for wear Check the groove on the piston pin retainer for wear (visual check) Check the camshaft for wear (visual check) Replace the camshaft bearings Check the length of the valve springs Check the spring cap for wear Check the eccentricity of the valve disk Check the valve guides for wear Check the radial clearanc
11-1C WIRING DIAGRAMS INDEX MODEL 2000 WIRING DIAGRAM USA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11-2 WIRING DIAGRAM EU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11-3 MODEL 2001 WIRING DIAGRAM EU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11-5 WIRING DIAGRAM USA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11-7 Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No.
Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No.
11-3C
Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No.
11-5C
Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No.
11-7C
Art.-No.
11-9C Modell: 250/400/520 EXC RACING
Repair manual KTM 250-525 SX, MXC, EXC RACING 250/400/520 EXC RACING 2002 Art.-No.
250/450/525 MXC / EXC 01/02/03 11-11C
Reparaturanleitung KTM 250/400/520 SX, MXC, EXC Racing Art.-Nr.
11-13C 2003 250/450/525 EXC Racing
