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KTM LC4 400-660LC42003 engine. Manual - part 10

6-9D

Mounting the clutch discs

– Thoroughly oil the O-ring

and put it onto the inner clutch hub.

– Oil the lining disc

(internal diameter: 127 mm) and mount it,

making sure that the disc encircles the O-ring (see illustration).

– Thoroughly oil all clutch discs before mounting.
– Alternately mount 1 steel disc and one lining disc.

NOTE: The last disc must be a lining disc.

CAUTION

OUNT ALL STEEL DISKS WITH THE SHARP EDGE FACING DOWNWARD

– Grease the end of the push rod with Molykote grease and fit the

pressure cap together with the push rod.

– When mounting the pressure cap make sure that bore

in the

pressure cap and the pin

of the inner clutch hub coincide.

– Place the springs in the pressure cap and fit the HH srews with spring

retainers.

– Secure carefully to 6 Nm in a diagonal pattern, to avoid any damage

to the inner clutch hub thread.

NOTE:
– Use offset instead of flat spring retainers for 640 ccm engines.
– From model 2000 onwards spring retainers 6,5x20x2 replaced spring

retainers 6,2x20x3,2, these can be used for all models with 540, 620
and 640 engines.

Installing the clutch release shaft

– Oil needle bushings in engine housing.
– Insert the grooved ring

into the housing with the open side up.

– Check for the right position of the circlip

on the clutch release

shaft.

– Slide the release shaft into the housing until it lies on the clutch push

rod.

6-10D

Repair manual KTM LC4

Art.-Nr

. 3.206.006 -E

– Turn the release shaft clockwise until it glides a bit further into the

housing. The push rod now sits on the release shaft.

– Apply Loctite 243 to the bolt (s).
– Fasten the retaining bracket for the clutch release

with bolt(s).

Adjusting the clutch release

– Turn the clutch release shaft clockwise to stop.
– The slot on the front side of the release shaft should now be parallel

to the sealing surface of the housing (see ill.).

– To adjust the clutch release remove pin

and turn the push rod

with a screwdriver until the desired setting is achieved.

– Once you have completed the adjustment, the push rod is to be

secured with a pin.

CAUTION

O MAKE SURE THAT THE CLUTCH DISENGAGES PERFECTLY

THE CLUTCH RELEASE

MUST BE PROPERLY ADJUSTED

Measure the dimension „Y" (from model 2003 on)

NOTE: The dimension „Y" must be adjusted to make sure the clutch
release operates correctly.
The dimension „Y" is the distance between the sealing area of the
clutch slave cylinder and the pushrod.
– Oil the pushrod and insert in the main shaft all the way in to the

stop.

– Measure the distance between the mounting face (without the

gasket) of the clutch slave cylinder to the pushrod using a depth
gauge.

– To adjust, remove the splint

and turn the pushrod

with a

screwdriver.

– After making the adjustment, lock the pushrod with the splint again.

Dimension „Y" = 2.75 mm

Mounting piston and cylinder

– Lubricate the piston pin eye in the connecting rod and the piston pin

with oil.

– Mount piston and secure piston pin with 2 new wire circlips.

CAUTION

HE ARROW ON THE PISTON HEAD MUST POINT IN THE DIRECTION OF TRAVEL

OUNT WIRE CIRCLIPS IN

„6

’

CLOCK

”

„12

’

CLOCK

”

POSITION

(

SEE ILL

.).

DIMENSION „Y“

Sealing surface of the clutch

slave cylinder

push

rod

12 o’clock-pos.

6 o’clock-pos.

6-11D

– Cut off the section of the housing gasket protruding around the

cylinder flange and mount 2 dowels.

– Apply sealing compound to the sections near the chain tunnel and

mount the cylinder base gasket.

NOTE:
– To facilitate the installation of the cylinder it is recommended to

place a rubber band (see illustration) around the timing chain guide
and the timing chain tensioner.

– Oil the piston, adjust the piston rings (piston rings must be turned

120 ° against each other) and mount the piston mounting ring.

– Only for 640 LC4 engines a black cylinder base gasket (0,7 mm

thickness) is used, the other LC4 engines need the green gasket
(0,5mm thickness).

– Slide the cylinder over the piston and remove the mounting ring.

CAUTION

PPLY PARTICULAR CARE WHEN MOUNTING THE CYLINDER

! T

HE OIL SCRAPER RING

IS EXTREMELY FRAGILE

– Hook in the preassembled microfilter with the holding device onto

the rear studs and mount the collar nuts

at the cylinder base.

– Tighten collar nuts with 40 Nm (30 ft.lb.) crosswise.
– Then mount the bracket

and attach the microfilter.

NOTE: The upper edge of the piston is higher than the upper edge of
the cylinder when the cylinder is screwed down.

Mounting the cylinder head

– Check both dowels within the cylinder for proper fit.
– Mount cylinder head gasket and fit cylinder head.
– Oil the 4 bolt (threads and contact surfaces of bolt head) and then

mount with new copper seal rings.

– Tighten collar bolts crosswise in three rounds up to the prescribed

torque of 50 Nm. During the first round only tighten until a slight
resistance is felt.

– Mount M8 collar nuts

on the front and rear side of cylinder and

tighten.

– Mount and tighten bolts

– Put a new seal ring on the chain guide bolt

and degrease the

thread.

– Apply Loctite 243 to the thread of the chain guide bolt, mount and

tighten it (30 Nm).

CAUTION

EFORE MOUNTING THE CHAIN GUIDE BOLT MAKE SURE THAT THE OPENING OF THE

TIMING CHAIN GUIDE IS VISIBLE THROUGH THE THREADED HOLE

. I

F THIS IS THE CASE

THE CHAIN GUIDE BOLT CAN EASILY BE MOUNTED WITHOUT EXERTING EXCESSIVE
FORCE

6-12D

Repair manual KTM LC4

Art.-Nr

. 3.206.006 -E

Mounting the camshaft, timing marks

– Fit the camshaft gear into the timing chain so that mark

(a point)

is aligned with the top surface of the cylinder head when the timing
chain strand tensioned.

– Tilt engine to one side and place circlip

on camshaft gear.

– Slide grooved ball bearing flush onto the preassembled camshaft and

fit the camshaft into the camshaft gear so that the mark

and mark

are aligned.

tensioned

6-13D

– Lubricate the needle bushing

with oil and slide it onto the

camshaft.

– Mount camshaft together with bearing and circlip

into cylinder

head.

– Degrease the threads in the camshaft and the driving bolt and apply

Loctite 243.

– Mount the driving bolt together with the lock washer and the

washer (10x28x3 mm) and tighten (35 Nm/25 ft.lb).

Mounting the water pump

– Loosen crankshaft locking bolt and turn crankshaft until groove

at a position vertical to the sealing surface for the cylinder head top
section.

– Coat O-ring of water pump with sealing compound (Three-Bond)

and carefully mount the water pump. The flat part of the water
pump shaft must be introduced into the groove of the HH bolt.

CAUTION

HE MARKING

LOCATED ON THE HOUSING OF THE WATER PUMP MUST BE FLUSH

TO THE SEAL SURFACE

6-14D

Repair manual KTM LC4

Art.-Nr

. 3.206.006 -E

Mounting the cylinder head top section

– Clean the sealing area of the cylinder head top section and apply a

thin layer of sealing compound.

– Fit dowel in the area of the spark plug.
– Carefully position cylinder head top section (do not jam with water

pump) and mount bolts.

CAUTION

OPPER SEAL RINGS MUST BE FITTED TO THE

5 A

LLEN HEAD BOLTS

AND

–

Tighten bolts

and

to 8 Nm diagonally.

–

Tighten bolts

to 15 Nm.

–

Tighten all other bolts of the cylinder head top section with 8 Nm.

Mounting the automatic tensioner

– Fit preassembled automatic tensioner with gasket into the cylinder.
– Mount the clamp

and two bolts with copper seal rings.

CAUTION

F THE RATCHETING PAWL IS NOT ENGAGED INTO THE FIRST NOTCH THIS WILL CAUSE

EXCESSIVE TENSION OF THE CHAIN

– Fit pressure spring and plug

with gasket and tighten with 20 Nm.

Automatic decompression testing

– Rotate the crankshaft in the usual direction of rotation (i.e. forward).

After every other rotation, the decompression cam must be clearly
heard to click as it disengages.

NOTE: If turning of the engine does not produce a click of the
decompression cam, first of all check the tightening torque of the
driving bolt (camshaft gear).

6-15D

Adjustment of valve clearance

– Adjust piston to ignition top dead center (check marks of flywheel)

and screw crankshaft locking bolt back in.

CAUTION

F THE PISTON IS NOT IN IGNITION

TDC,

VALVES ARE OPENED AND A CORRECT

ADJUSTMENT IS NOT POSSIBLE

IN THAT CASE CRANKSHAFT MUST BE MOVED A FULL

TURN

– Valve clearance

is measured at cold engine between valve stem

and adjusting screw.

VALVE CLEARANCE 400 : INTAKE 0.20 mm / EXHAUST 0.20 mm
VALVE CLEARANCE 540 : INTAKE 0.15 mm / EXHAUST 0.15 mm
VALVE CLEARANCE 620 : INTAKE 0.15 mm / EXHAUST 0.15 mm
VALVE CLEARANCE 625 : INTAKE 0.15 mm / EXHAUST 0.15 mm
VALVE CLEARANCE 640 : INTAKE 0.15 mm / EXHAUST 0.15 mm
VALVE CLEARANCE 660 : INTAKE 0.15 mm / EXHAUST 0.15 mm

– Tighten counternuts with 20 Nm.
– Remove the crankshaft locking bolt.

– Mount both valve covers with new gaskets and bolts with copper

seal rings.

– Tighten bolts with 8 Nm.
– Insert and tighten spark plug with 20 Nm.

Mounting the clutch cover

– Pour approx. 30 ml of oil into the crankshaft journal hole.

– Make sure that the two dowels are mounted.
– Fit new gasket and fix with dabs of grease.
– Apply grease to the shaft seal ring in the clutch cover and mount

clutch cover.

– Fit bolts and bump rubber

for kickstarter.

NOTE: Bolts

must each be provided with a copper seal ring.

– Tighten bolts with 8 Nm.

6-16D

Repair manual KTM LC4

Art.-Nr

. 3.206.006 -E

Mounting the electric starter drive

– Insert the woodruff key into the crankshaft.
– Slide 2 needle bearings

onto the bearing pin of the reduction gear.

– Slide the needle bearing

onto the crankshaft.

– Oil the needle bearings.

– Mount the freewheel gear

and the reduction gear

Mounting the ignition (Kokusan 4K-2)

– Degrease the cones of flywheel and crankshaft.
– Thoroughly oil the freewheel and mount the flywheel.

NOTE: Turn the reduction gear for easier mounting of the flywheel.

– Mount disk with the nut.
– Use the holding tool

to hold the flywheel and tighten the

hexagon nut with 150 Nm.

CAUTION

O AVOID DISTORTION OF THE CRANK WEB

NEVER MOUNT THE CRANKSHAFT

LOCKING BOLT TO TIGHTEN THE HEXAGON NUT OF THE FLYWHEEL

– Insert 2 dowels into the housing.
– Apply silicone to both sealing surfaces and mount a new gasket.
– Mount the preassembled starter flange and use 4 bolts to fasten the

starter flange.

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