250-525 SX, MXC, EXC RACING REPAIR MANUAL ENGINE KTM SPORTMOTORCYCLE AG 5230 Mattighofen Austria www.ktm.at 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 IMPORTANT INFORMATION/UPDATING 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: 14, 21-24, 30-47, 50-52, 56-76, 79-92, 97-124, 134-140, 142, 150-154, 165-167 Remove page (s) 2-1 / 2-7 3-1 4-1 to 4-14 5-1 / 5-3 5-6 to 5-8 5-12 to 5-26 6-1 / 6-4 6-7 to 6-16 7-1 to 7-2 Art.-No. 3206007 -E Replace by page (s) 2-1C 3-1C 4-1C to 4-13C 5-1C / 5-3C 5-6C to 5-8C 5-12C to 5-27C 6-1C / 6-4C 6-7C to 6-17C 7-1C to 7-2C 7-7C to 7-11C 8-1C to 8-21C 9-1C 9-10C to 9-16C 10-1C 11-1C Insert page (s) 2-7C to 2-9C after page 7-7 to 7-11 8-1 to 8-13 9-1 9-10 to 9-13 10-1 11-1 10-8C to 10-11C 11-11C to 11-13C KTM REPAIR MANUAL IN LOOSE-LEAF FORM Repair manual KTM 250-525 SX, MXC, EXC RACING STORING THE REPAIR MANUAL IN THE BINDER ­ Put the index into the binder. ­ Put the front page of the repair manual (210x297 mm) into the transparent pocket provided for this purpose on the outside of the binder. ­ Put the spine label (170x45 mm) into the transparent pocket provided for this purpose on the spine of the binder. ­ Put the summary list of contents (150x297 mm) into the transparent pocket provided for this purpose on the inside of the binder or insert this page on the beginning of the manual. ­ Then insert the individual chapters of the manual between the sheets of the index according to the page number printed in the right bottom corner of each page. Example: page no. 3-5 3 = chapter 3 5 = page 5 All pages with a page number that begins with the digit 3, for example, must be put under the index heading ,,Chapter 3". ­ Index sheets that have not been marked with a certain chapter are for your personal convenience. The respective headings can be entered in the list of contents. EXPLANATION - UPDATING 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") 1/2001 Art.-No. 3206007 -E 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 3.205.85-E Model year 2003 (Engine number with first digit "3") Repair manual KTM 250-525 SX, MXC, EXC RACING 1/2003 Modification / Updating: Technical Details Model 2003 (clutch, valve spring, camshaft gear, carburetor) Technical Specifications, Periodic Maintenance Schedule, Wiring Diagrams Edition 01/2003 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. We take it for granted that the repairs are made by qualified profesionally trained mechanics. Read through the repair manual before beginning with the repair work. WARNING STRICT COMPLIANCE WITH THESE INSTRUCTIONS ESSENTIAL TO AVOID DANGER TO LIFE AND LIMB. ! CAUTION ! IS NON-COMPLIANCE WITH THESE INSTRUCTIONS CAN LEAD TO DAMAGE OF MOTORCYCLE COMPONENTS OR RENDER MOTORCYCLES UNFIT FOR TRAFFIC ! ,,NOTE" POINTS OUT USEFUL TIPS. Use only ORIGINAL KTM SPARE PARTS when replacing parts. The KTM high performance engine is only able to meet user expectations if the maintenance work is performed regularly and professionally. KTM Austria's certificate of achievement for its quality system ISO 9001 is the beginning of an ongoing total reengineered quality plan for a brighter tomorrow. KTM Sportmotorcycle AG 5230 Mattighofen, Austria All design and assembly modification rights reserved. C by KTM SPORTMOTORCYCLE AG, AUSTRIA All rights reserved 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. To keep improving the quality of our repair manuals, we request mechanics and shop foremen to assist us as follows: If you find any errors or inaccuracies in one of our repair manual ­ whether these are technical errors, incorrect or unclear repair procedures, tool problems, missing technical data or torques, inaccurate or incorrect translations or wording, etc. ­ please enter the error(s) in the table below and fax the completed form to us at 0043/7742/6000/5349. ­ NOTE to table: Enter the complete item no. for the repair manual in column 1 (e.g.: 3.210.66-E). You will find the number on the cover page or in the left margin on each right page of the manual. Enter the corresponding page number in the repair manual (e.g.: 5-7c) in column 2. Enter the current text (inaccurate or incomplete) in column 3 by quoting or describing the respective passage of the text. If your text deviates from the text contained in the repair manual, please write your text in German or English if possible. Enter the correct text in column 4. ­ ­ ­ Your corrections will be reviewed and incorporated in the next issue of our repair manual. Item no. of repair manual Page Current text Correct text Additional suggestions, requests or comments on our Repair Manuals (in German or English): Name mechanic/shop foreman Company/work shop 2-1C GENERAL INFORMATION INDEX 2 OIL CIRCUIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ENGINE OIL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CHECKING THE ENGINE OIL LEVEL . . . . . . . . . . . . . . . . . CHANGING THE ENGINE OIL . . . . . . . . . . . . . . . . . . . . . . CHANGING THE OIL FILTERS . . . . . . . . . . . . . . . . . . . . . . CHECKING THE OIL LEVEL OF THE HYDRAULIC CLUTCH BLEEDING OF THE HYDRAULIC CLUTCH . . . . . . . . . . . . . SPECIAL TOOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CLEANING, STORAGE OF MOTORBIKE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2 . . .2-3 . . .2-3 . . .2-4 . . .2-5 . . .2-6 . . .2-6 . . .2-7 . . .2-9 Repair manual KTM 250-525 SX, MXC, EXC RACING Art.-No. 3206007 -E 2-2C 3 7 4 6 5 8 11 10 13 1 12 9 2 Art.-No. 3206007 -E 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. Then, the engine oil arrives at the short oil filter 7 which also filters the fine particles. Now, the purified engine oil is pumped past the bypass valve 8 to the conrod bearing 9 and sprayed from below onto the piston through a nozzle bk. The second oil pump bl draws the engine oil via the short oil screen bm out of the crankcase, thereby lubricating the transmission gears bn. Repair manual KTM 250-525 SX, MXC, EXC RACING 2-3C Engine oil API: SG, SH TEMPERATURE 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). ­ 10W 40 10W 50 0°C 32°F + 15W 40 15W 50 ! INSUFFICIENT THE ENGINE. CAUTION ! AMOUNTS OR LOW-GRADE ENGINE OIL LEAD TO PREMATURE WEAR OF Checking the engine oil level The engine oil level can be checked with the engine being either warm or cold. Place the motorcycle in an upright position and on a horizontal surface (not on the side stand). If the engine is cold, the engine oil must be visible at the lower edge of the inspection glass A. B A If the engine is warm, the engine oil must be visible up to the upper edge of the inspection glass B. Replenish the engine oil, if necessary. ! INSUFFICIENT THE ENGINE. CAUTION ! AMOUNTS OR LOW-GRADE ENGINE OIL LEAD TO PREMATURE WEAR OF NOTE: Engines up to the 2001 model have a sight glass and an oil dipstick. If the inspection glass is heavily soiled (e.g. after a race in muddy terrain), the engine oil level can also be measured with the oil dipstick. For this purpose, unscrew the dipstick and wipe it clean with a cloth. Screw the dipstick back in and screw it out again. If the engine is warm, the oil level should be near the MAX mark C. Check engine for leaks. C 2-4C Changing the engine oil 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. Once the entire oil has been drained, clean the sealing surface, mount the plug together with the sealing ring and tighten it to 20 Nm/ 15ft.lb. CLEANING THE SHORT OIL SCREEN The short oil screen 2 is accommodated in the hex-socket plug 3 on the engine bottom. Insert a pin-type key into the plug and tap on the key a few times with a hammer in order to relieve the stress acting on the plug. Dismount the oil screen, clean the components thoroughly and blow compressed air through them. Check the O-rings for damage and, if necessary, replace them. Mount the oil screen together with the plug again and tighten the plug to 10 Nm. 1 2 3 Art.-No. 3206007 -E CLEANING THE LONG OIL SCREEN The long oil screen is accommodated in the hexagon plug 4 adjacent the engine number. Dismount the plug together with the oil screen, clean the components thoroughly and blow compressed air through them. Check the O-rings for damage and, if necessary, replace them. 4 Repair manual KTM 250-525 SX, MXC, EXC RACING 5 To mount the long oil screen 5, place it on an approx. 300 mm/ 11.8 in long pin-type key or a similar tool. Insert the pin-type key through the opening into the bore of the opposite engine casing wall. Then, push the oil screen into the engine casing as far as possible. Remove the pin-type key, mount the plug and tighten it to 15 Nm/ 11 ft.lb. ! CAUTION ! THE OIL SCREEN IS MOUNTED SLIGHTLY DOWNWARDS, IF INCORRECTLY FITTED, THE SCREEN LOOSES ITS FUNCTION AND THIS CAN CAUSE INCREASED ENGINE WEAR. 2-5C Changing the oil filters 1 2 2 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 3 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. 3 4 Put the motorcycle on its side and fill the oil filter housings about halfway with engine oil. Insert the long oil filter at the front and the short oil filter at the back of the housing. Grease the O-rings 4 of the oil filter covers and mount the cover. Mount the bolts and tighten them to 6 Nm/5 ft.lb. Position the brake fluid container and tighten the bolt to 8 Nm/ 6 ft.lb. Return the motorcycle to an upright position. Remove the oil dipstick 5 at the clutch cover and fill in 1.2 liters of fully synthetic engine oil (Motorex Power Synt. 4T). 5 Start the engine and check all screwed connections and oil filter covers for leaks. Finally, check the engine oil level and, if necessary, correct it. 2-6C 1 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. NEVER USE BRAKE FLUID! 2 Bleeding of the hydraulic clutch For bleeding, the cover of the master cylinder of the clutch needs to be removed. For this purpose, remove screws 1 and take off cover together with rubber bellows 2. At the slave cylinder of the clu ...