KTM 250 SX User Manual

Repair manual KTM 250 / 300 / 380 Art No 3206004 -E
250/300/380 SX,MXC,EXC
REPAIR MANUAL
ENGINE
KTM SPORTMOTORCYCLE AG
5230 Mattighofen Austria www.ktm.at
MANUAL
ENGINE
250 - 380
SX,MXC,EXC
1 SERVICE-INFORMATIONS
2 GENERAL INFORMATION
3 REMOVING AND REFITTING ENGINE
4 DISASSEMBLING THE ENGINE
5
SERVICING ON INDIVIDUAL COMPONENTS
6 ASSEMBLING THE ENGINE
7 ELECTRICAL
8 TROUBLE SHOOTING
9 TECHNICAL SPECIFICATIONS
10 PERIODIC MAINTENANCE SCHEDULE
11 WIRING DIAGRAMS
12
13
14
15
16
Repair manual KTM 250 / 300 / 380 Art No 3206004 -E
Remove page (s) Replace by page (s) Insert page (s) after page
2-1 to 2-4 2-1C to 2-6C
3-4 3-4C
4-1 to 4-9 4-1C to 4-8C
5-1 5-1C
5-4 5-4C / 5-5C
5-13 to 5-14 5-13C to 5-14C
7-1 7-1C 7-5C to 7-10C
9-1 9-1C 9-37C to 9-42C
10-1 10-1C 10-6C to 10-8C
11-1 11-1C 11-14C to 11-16C
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:
14-20, 26, 28-36, 37, 41, 42, 50, 51, 67, 72-77, 83, 121-126, 127, 134-136,
137, 151-153
KTM REPAIR MANUAL IN LOOSE-LEAF FORM
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
Edition 11/2002
Repair manual KTM 250 / 300 / 380 Art No 3206004 -E
3.205.63-E Repair Manual 250 / 300 / 380 SX, MXC, EXC
Basicversion Modelyear 1999 (Engine number with first digit “9“)
11/1998
3.205.87-E Updating of Rep.Manual 3.205.63-E
Modelyear 2000 (Engine number with first digit “0“)
2/2000
3.210.02-E Updating of Rep.Manual 3.205.63-E
Modelyear 2001/2002 (Engine number with first digit “1“) (Engine number with first digit “2“)
3/2001
3.206.004-E Updating of Rep.Manual 3.205.63-E
Modelyear 2003 (Engine number with first digit “3“)
11/2002
Modification / Updating: Technical Specification, Periodic Maintenance Schedule, Wiring Diagrams

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 IS ESSENTIAL TO AVOID DANGER TO LIFE AND LIMB.
!
CAUTION
!
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 on going 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
Repair manual 250 / 300 / 380 Art Nr 3206004 -E
OPERATING RANGES OF THE CARBURETOR . . . . . . . . . . . . . . . . . . .2-2
CARBURETOR ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3
CHECKING OF THE SETTING OF THE TVC SYSTEM . . . . . . . . . . . . . .2-4
BLEEDING OF THE HYDRAULIC CLUTCH . . . . . . . . . . . . . . . . . . . . .2-4
SPECIAL TOOLS - ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6
STORAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6
INDEX
2-1C

GENERAL INFORMATION

2
Repair manual KTM 250 / 300 / 380 Art No 3206004 -E
2-2C
main jet jet needle
jet needle
air control screw idle adjusting screw
idle jet throttle valve
Idling range A
Operation with closed throttle valve. This range is influenced by the position of the air control screw 1 and the idle adjusting screw
2. Only make adjustments when the engine is hot.
To this end, slightly increase the idling speed of the engine by means of the idle adjusting screw. Turning it clockwise produces a higher idling speed and turning the screw counterclockwise produces a lower idling speed. Create a round and stable engine speed using the air control screw (basic position of the air control screw = open by 1.5 turns). Then adjust to the normal idling speed by means of the idle adjusting screw.
Opening up B
Engine behavior when the throttle opens. The idle jet and the shape of the throttle valve influences this range. If, despite good idling-speed and part-throttle setting, the engine sputters and smokes when the throttle is fully opened and develops its full power not smoothly but suddenly at high engine speeds, the mixture to the carburetor will be too rich, the fuel level too high or the float needle is leaking.
Part-throttle range C
Operation with partly open throttle valve. This range is only influenced by the jet needle (shape and position). The optimum part-throttle setting is controlled by the idling setting in the lower range and by the main jet in the upper range. If the engine runs on a four-stroke cycle or with reduced power when it is accelerated with the throttle partly open, the jet needle must be lowered by one notch. If then the engine pings, especially when accelerating under full power at maximum engine revs, the jet needle should be raised. If these faults should occur at the lower end of the part throttle range at a four-stroke running, make the idling range leaner; if the engine pings, adjust the idling range richer.
Full throttle range D
Operation with the throttle fully open (flat out). This range is influenced by the main jet and the jet needle. If the porcelain of the new spark plug is found to have a very bright or white coating or if the engine rings, after a short distance of riding flat out, a larger main jet is required. If the porcelain is dark brown or black with soot the main jet must be replaced by a smaller one.
mixture too rich:
too much fuel in proportion to air
mixture too lean:
not enough fuel in proportion to air
1
2

OPERATING RANGES OF THE CARBURETOR

2-3C

Carburetor adjustment

Basic information on the original carburetor setting
The original carburetor setting was adapted for an altitude of approx. 500 meters (1600 ft.) above sea level, and the ambient temperature of approx. 20° C (68° F), mainly for off-road use and central European premium-grade fuel (ROZ 95 MOZ). Mixing ratio 2-stroke motor oil : super fuel 1:40 – 1:60.
Basic information on a change of the carburetor setting
Always start out from the original carburetor setting. Essential requirements are a clean air filter system, air-tight exhaust system and an intact carburetor. Experience has shown that adjusting the main jet, the idling jet and the jet needle is sufficient and that changes of other parts of the carburetor will not greatly affect engine performance.
RULE OF THUMB:
high altitude or high temperatures
choose leaner carburetor adjustment
low altitude or low temperatures
choose richer carburetor adjustment
WARNING
–O
NLY USE PREMIUM
-GRADE GASOLINE ROZ 95 MIXED WITH HIGH-GRADE TWO-STROKE ENGINE OIL. OTHER TYPES OF GASOLINE CAN CAUSE ENGINE
FAILURE
, AND USE OF SAME WILL VOID YOUR WARRANTY.
–O
NLY USE HIGH-GRADE 2-STROKE ENGINE OIL OF KNOWN BRANDS.
–N
OT ENOUGH OIL OR LOW
-GRADE OIL CAN CAUSE EROSION OF THE PISTON. USING TOO MUCH OIL, THE ENGINE CAN START SMOKING AND FOUL THE
SPARK PLUG
.
–I
N THE CASE OF A LEANER ADJUSTMENT OF THE CARBURETOR PROCEED CAUTIOUSLY
. ALWAYS REDUCE THE JET SIZE IN STEPS OF ONE NUMBER TO AVOID
OVERHEATING AND PISTON SEIZURE
.
NOTE: If despite a changed adjustment the engine does not run properly, look for mechanical faults and check the ignition system.
Basic information on carburetor wear
As a result of engine vibrations, throttle valve, jet needle, and needle jet are subjected to increased wear. This wear may cause carburetor malfunction (e.g., overly rich mixture). Therefore, these parts should be replaced after 10000 kilometers (6000 miles).
Explanation - Example
Compared to the needle N 85 A, the jet needle N 85 C is two steps leaner in the range from the closed position of the throttle to 1/4 throttle. Otherwise, there are not differences.
!
CAUTION
!
W
HEN CHANGING THE JET NEEDLE, MAKE SURE THAT YOU USE THE CORRECT NEEDLE
TYPE
(N 85 ,NOZ OR N3). THE TECHNICAL DATASHEET TELLS YOU WHICH JET
NEEDLE CAN BE USED FOR WHICH MODEL
.
N 85 C
0
–1/4 – –
jet needle throttle valve open effect
N 85 A N 85 B 0
–1/4 –
N 85 C 0
–1/4 – –
N 85 D 0
–1/4 – – –
N 85 E 0
–1/4 – – – –
NOZ C NOZ D 0
–1/4 –
NOZ E 0
–1/4 – –
NOZ F 0
–1/4 – – –
NOZ G 0
–1/4 – – – –
NOZ H 0
–1/4 – – – – –
NOZ I 0
–1/4 – – – – – –
NOZ J 0
–1/4 – – – – – – –
N3CG N3CH 0
–1/4 –
N3CW 0
–1/4 – –
Repair manual KTM 250 / 300 / 380 Art No 3206004 -E
2-4C
Checking the setting of the TVC system
The function of the TVC system is checked with the engine running. This test checks the start of advance and the end of advance.
– For this, remove the left control cover. – Connect a rev counter (either to the ignition cable or to the blue/white
cable in the electronics box, depending on the rev counter design).
– Start engine, accelerate gently and observe when the TVC system
starts to advance (tooth segment creeps upwards).
– If necessary, turn the adjusting screw
1.
NOTE: Twisting the adjusting screw in delays the commencement of adjustment by the TVC system, twisting the adjusting screw out means that the TVC system will perform the adjustment earlier.

Bleeding of the hydraulic clutch

–Take off cover together with rubber bellows. – At the slave cylinder of the clutch, remove the bleeder nipple
2. It its
place, mount the bleeder syringe
3 which is filled with SAE 10
hydraulic oil.
– Refill oil, until oil is discharged from the bore
4 of the master cylinder
in a bubble-free state. Make sure that the oil does not overflow.
!
CAUTION
!
–HAVING COMPLETED THE BLEEDING PROCEDURE, YOU HAVE TO VERIFY THAT THE
OIL LEVEL IN THE MASTER CYLINDER IS CORRECT
.
– KTM
USES BIODEGRADABLE HYDRAULIC OIL FOR THE HYDRAULIC CLUTCH
CONTROL
. NEVER MIX BIODEGRADABLE HYDRAULIC OILS WITH MINERAL OILS.
–ALWAYS USE BIODEGRADABLE HYDRAULIC OIL SAE 10 TO FILL UP THE MASTER
CYLINDER
. NEVER REFILL WITH MINERAL HYDRAULIC OIL OR BRAKE FLUID.
1
start of advance end of advance
250 Model 1999 5400 U/min 7550 U/min
250 from Modell 2000 on 5000 U/min 7000 U/min
300 up to Modell 2000 5300 U/min 7750 U/min
300 from Modell 2001 on 5900 U/min 7750 U/min
380 5200 U/min 7200 U/min
2
3
4
2-5C
Fig. Part no. Description
1 560.12.001.000 Universal engine work stand 3 546.29.003.000 Clutch holder 4 560.12.004.000 Gear wheel segment 5 546.29.009.044 Magneto extractor M 27x1 Kokusan 66 276 807 Magneto extractor M 26x1,5 SEM 7 510.12.011.000 Circlip plier 8 544.12.012.000 Holding spanner for flywheel SEM 9 584.29.037.040 Mounting tool inner ring NJ 207
9 584.29.037.043 Mounting tool inner ring NJ 207 10 510.12.016.000 Protection cap 11 546.29.012.100 Holding spanner for flywheel Kokusan 13 501.12.013.000 Dial gauge 0-10 mm 14 501.12.030.000 Dial gauge support 16 6 899 785 Loctite 243 blue 6 ccm 17 151.12.017.000 Bearing puller 18 151.12.018.100 Internal bearing puller 18-23 mm 18 151.12.018.000 Internal bearing puller 12-16 mm 18 151.12.018.200 Internal bearing puller 5-7 mm 19 546.29.027.000 Clutch rivetting tool 25 0276 179 000 Extractor primary gear 26 503.29.050.000 Vent springe for hydraulic clutch
SPECIAL TOOLS – ENGINE 250 / 300 / 380
13
14
1
7
9
16
4
26
10
8
5
19
6
11
17
18
25
3
Repair manual KTM 250 / 300 / 380 Art No 3206004 -E
2-6C
Should you wish to make a pause over a longer space of time, please observe the following instructions:
– Clean motorcycle thoroughly (see chapter: CLEANING) – Change engine oil (old engine oil contains aggressive contaminants). – Check antifreeze and amount of cooling liquid. – Let the engine warm up again, close fuel cock 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 ccm of engine oil into the cylinder through the opening. Actuate kick-starter 10 times in order
to distribute the oil onto the cylinder walls and mount the spark plug. – Let fuel flow out of tank into an appropriate container. – 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 too big temperature fluctuations. – Cover the motorcycle with an air permeated tarp or blanket. Do not use non airtight materials as a possible humidity might not be
able to escape and thereby cause corrosion.
!
CAUTION
!
I
T 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 VALVES AND EXHAUST TO RUST
.
USE AFTER A PERIOD OF STORAGE
– Fill up the tank with fresh fuel. – Check the 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.

STORAGE

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. THE WATER COULD OTHERWISE RUN INTO THE
ELECTRICAL COMPONENTS
, CONNECTORS, SHEATHED CABLES, BEARINGS, CARBURETOR, ETC. AND CAUSE DISTURBANCES OR LEAD TO A PREMATURE
DESTRUCTION OF THESE PARTS
.
– Before cleaning with water, plug the exhaust pipe to prevent water ingress. –You should use normal brand-name detergents to clean the motorcycle. Especially dirty parts should also be cleaned with the help
of a paint brush.
–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 the working temperature and also use the brakes. By warming these components, the residual water can evaporate from inaccessable parts of the engine and the brakes.
– 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. Treat the chain with a chain spray. –To prevent failures in the electric system, you should treat the ignition lock, the emergency OFF switch, the short circuit button, the
light switch and the socket connectors with contact spray.

CLEANING

In the event that the motorcycle is also used in winter and on roads where one has to expect salt spraying, you will have to take precautions against the aggressive road salt. – clean the motorcycle thoroughly and let it dry after each ride –treat the engine, carburetor, swing arm, and all other bare or galvanized parts (except for brake discs) with a wax-based anti-corro-
sion agent.
WARNING
K
EEP THE ANTI-CORROSION AGENT FROM GETTING INTO CONTACT WITH THE BRAKE DISCS, OTHERWISE THIS WILL SIGNIFICANTLY REDUCE THE BRAKING POWER
.
!
CAUTION
!
A
FTER RIDES ON SALTED ROADS, CLEAN MOTORCYCLE THOROUGHLY WITH COLD WATER AND LET IT DRY WELL.
CONSERVATION FOR WINTER OPERATION
Repair manual 250 / 300 / 380 Art No 3206004 -E

REMOVING AND REFITTING ENGINE

REMOVING THE ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2
REFITTING THE ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4
INDEX
3-1C
3
Repair manual KTM 250 / 300 / 380 Art No 3206004 -E
Dismounting the engine
– Clean motorcycle thoroughly. –Prop up motorcycle on an appropriate stand. – Remove seat, right side paneling, and tank with spoilers.
– Dismount exhaust system.
– Drain coolant, and disconnect radiator hoses from engine. – Dismount engine strut
1.
– Disconnect plug-and-socket connector of ignition system and spark-
plug connector.
– Remove sprocket cover
2 and chain.
– Remove footbrake cylinder cover
3.
– Disengage and remove spring
4.
3-2C
1
2
3
4
– Loosen the 3 screws, and remove intermediate flange chamber 1 of
KTC system together with O-ring.
– Remove engine fastening screw
2.
– Remove cable ties and loose the cable of ignition from frame.
– Loosen both hose clamps, and pull caburetor out of carburetor
connection boot and intake flange.
– Remove transmission-oil drain plug
3 together with sealing ring, and
drain the transmission oil.
– Remove the 2 screws
4, and dismount clutch slave cylinder.
!
CAUTION
!
D
O NOT ACTUATE THE CLUTCH LEVER WITH THE CLUTCH SLAVE CYLINDER
DISMOUNTED
.
– Remove engine fastening screw
5.
– Remove hexagon nut of swingarm pivot
6.
– Remove swingarm pivot, and pull swing arm backward out of the
frame so as to make lifting the engine out of the frame easier.
– Lift engine out of frame.
NOTE: Cylinder head and cylinder can be dismounted even if the engine remains mounted. Likewise, work on clutch, primary drive, gearshift mechanism, and ignition system can be carried out.
3-3C
1
3
5
2
4
4
6
Repair manual KTM 250 / 300 / 380 Art No 3206004 -E

Refitting the engine

–To install the engine, reverse the steps for removing the engine.
Filling in of transmission oil: – Remove the plug 1 and top up with engine oil 15W-50 (i. e.
MOTOREX TOP SPEED 4T).
– In order to check the transmission oil level the control screw
2 on the
clutch cover is to be removed. Oil should just barely escape from the inspection opening when the motorcycle is in an upright position.
!
CAUTION
!
T
RANSMISSION AND CLUTCH WILL BE SUBJECT TO AXCESSIVE WEAR AND TEAR, IF YOU
USE TOO LITTLE OR LOW GRADE OIL
. USE ONLY HIGH-GRADE OIL (I.E. MOTOREX
TOP SPEED 4T).
Filling in of cooling liquid: – Make sure that the drain screw 3 is fastened.
– Pour approx. 0.50 litres (0.13 US gallons) coolant into the system.
40% coolant : 60% water
– Remove the screw 4 on the right radiator and tilt the motorcycle to
the right approx. 30 degree angle.
– Now add cooling liquid until it emerges free of bubbles at the right
radiator. Then immediately mount the screw so that no more air can enter the right radiator.
– Return the motorcycle to its original position and top up the left
radiator until the coolant can be seen approx. 10 mm (0.4 in) above the radiator fins.
3-4C
4
2
3
1
Repair manual 250 / 300 / 380 Art No 3206004 -E

DISASSEMBLING THE ENGINE

DRAINING GEAR OIL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2
DISMOUNTING OF SPROCKET AND SHIFT LEVER . . . . . . . . . . . . . . .4-2
DISMOUNTING OF CYLINDER HEAD, CYLINDER AND PISTON . . . . .4-2
DISMOUNTING OF CLUTCH COVER . . . . . . . . . . . . . . . . . . . . . . . .4-3
DISMOUNTING OF PRESSURE CAP AND CLUTCH DISCS . . . . . . . . . .4-4
DISMOUNTING OF THE PRIMARY DRIVE . . . . . . . . . . . . . . . . . . . . .4-4
DISMOUNTING OF KICKSTARTER . . . . . . . . . . . . . . . . . . . . . . . . . .4-5
DISMOUNTING OF THE SHIFT LOCK . . . . . . . . . . . . . . . . . . . . . . . .4-5
DISMOUNTING OF IGNITION COVER . . . . . . . . . . . . . . . . . . . . . . .4-5
DISMOUNTING OF THE IGNITION (KOKUSAN) . . . . . . . . . . . . . . . . .4-6
DISMOUNTING OF THE IGNITION (SEM) . . . . . . . . . . . . . . . . . . . . .4-6
DISMOUNTING OF INTAKE FLANGE AND REED VALVE HOUSING . . .4-7
PARTING OF ENGINE HOUSING HALVES . . . . . . . . . . . . . . . . . . . . . .4-7
DISMOUNTING OF GEARSHIFT MECHANISM AND TRANSMISSION . .4-7
DISMOUNTING OF THE CRANKSHAFT . . . . . . . . . . . . . . . . . . . . . . .4-8
INDEX
4-1C
4
4-2C
Repair manual KTM 250 / 300 / 380 Art No 3206004 -E
– Cleaning the engine thoroughly. – Clamp the engine into the workstand. – Remove the kickstarter together with the distance bushing behind.

Draining gear oil

NOTE: The transmission oil should already be drained when the engine is dismounted. Otherwise, the transmission oil will leak out of the drive shaft following the removal of the slave cylinder of the clutch.
– Unscrew plug
1, allowing oil to drain.

Dismounting of sprocket and shift lever

– Remove circlip 2 from countershaft using circlip pliers. Slide off engine
sprocket, distance bushing and O-ring.
– Undo the screw
3 and remove the shift lever.
– Pull out the clutch push rod
4 from drive shaft.

Dismounting of cylinder head, cylinder and piston

– Unscrew the 6 collar screws 5 and remove cylinder head and the two
O-rings.
– Undo the screws
6 and remove the left control cover together with
the gasket.
1
2
3
4
5
6
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