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KTM LC4 400-660LC42003 engine. Manual - part 7

Repair manual KTM LC4

Art.-Nr

. 3.206.006 -E

Disassembling the cylinder head top section and checking
the components for wear

– Simply pull the rocker arm axles

out of the cylinder head top

section. Then take both rocker arms

together with thrust washers

and

out of the cylinder head top section.

Undo bolt

and remove

the following components:

Washer

Decompression shaft lever

Covering disc

O-ring

Decompression lever spring

– Press the decompression shaft

inwards and take it out of the

cylinder head top section together with the washers

– Clean all components.

Rocker arm shafts

The rocker arm shafts must be free of grooves and should turn easily
within the rocker arms

Rocker arm rollers

The rocker arm rollers must move smoothly. Rocker arm rollers must be
removed in the case of radial clearance.

Adjusting screws

The contact surfaces of the adjusting screws must be plane.

Decompression shaft

Check for smooth operation and clearance in the bearing bore.

Pre-assembling the cylinder head top section

– Insert decompression shaft

with compensation washers

into the

top section.

– Mount the new O-ring

, the decompression lever spring

and

the cover disc

in such a way that the O-ring fits into the recess of

the cover disc.

– Mount the decompression shaft lever

– Apply Loctite 243 to the thread of bolt

and mount the bolt

together with washer

– Hook the decompression lever spring onto the decompression shaft

lever.

CAUTION

HE DECOMPRESSION SHAFT MUST EXHIBIT NO AXIAL PLAY WHEN THE ALLAN HEAD

BOLT

IS TIGHTENED

. T

O ENSURE THAT THE O

RING

ORMS A SEAL

IT MUST BE

SLIGHTLY PRESSED AGAINST THE TOP SECTION BY THE COVER DISC

. H

OWEVER

THE

PRESSURE

THE

O-

RING

MUST

NOT

EXCESSIVELY

HIGH

THE

DECOMPRESSION

SHAFT

WILL

BECOME

SLUGGISH

. A

DJUST

OUT

WITH

COMPENSATION WASHERS

IF NECESSARY

NOTE: Discs

are available 0.15 mm, 0.30 mm and 0.50 mm thick.

– Mount new O-rings

on rocker arm shafts

– Mount rocker arms

, thrust washers

and rocker arm shafts

– On the side of the water pump one thrust washer

≠ 1.0 mm (0.04

in) must be mounted.

– The axial play on the opposite side is roughly equalized with thrust

washers

≠ 1.0 (0.04 in) and ≠ 0.5 mm (0.02 in).

The axial clearance of the rocker arm axles must be 0.20 - 0.30 mm.

5-11D

LOCTITE 243

Checking the components of the timing mechanism for wear

Timing chain guide

Check for signs of wear.

Timing chain tensioner

Check for signs of wear.

Timing chain

Check rollers for smooth operation and signs of wear.

Timing gear

Check teeth for signs of wear.

Camshaft gear

Check teeth for signs of wear.

Grooved ball bearing

Check clearance.

Safety device

Check for signs of wear.

Camshaft

Check pivot points and running surfaces for signs of wear.

Disassembling the camshaft and checking the components
for wear

– Remove both the stepped ring

and the circlip

. Carefully

remove the decompression cam

. Keep a watch on the spring

Supporting pin

Check for signs of wear.

Guide pin

Check for signs of wear.

Decompression cam

Check the contact surfaces towards the supporting pin for signs of
wear.

Spring

Check length (minimum length: 7.0 mm/0.275 in).

Camshaft

Check for signs of wear at pivot point

. Minimum diameter of the

pivot point 19.97 mm.

Preassembling the camshaft

– Place spring

in the bore, compress and slide decompression cam

over it.

– Mount circlip

with the sharp side towards the decompression cam.

– Position the open side

of the circlip between the open spaces of

the decompression cam.

– Slide the step ring

with open spaces over the lock washer.

5-12D

Repair manual KTM LC4

Art.-Nr

. 3.206.006 -E

5-13D

Automatic tensioner

– Check ratcheting pawl

for smooth operation and wear.

– Check thrust bolt

for wear at teeth.

Preassembly of automatic tensioner

– Insert thrust bolt into tensioner housing and engage ratcheting pawl

into first notch (see illustration).

CAUTION

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

EXCESSIVE TENSION OF THE CHAIN

Disassembling the oil pumps and checking the components
for wear

NOTE: The two oil pumps are similar in design but work at different
speeds. Disassemble and check the oil pumps separately to avoid mixing
up of components.

– Remove screw

and take off the oil pump cover

– Pull the oil pump shaft

out of the oil pump housing together with

the bearing needle.

– Take the inner rotor

and the outer rotor

out of the oil pump

housing.

– Clean all components and check for signs of wear.

– When reassembling the unit insert the inner rotor and the outer rotor

into the oil pump housing, making sure that the point faces the
inside.

– Mount oil pump shaft and bearing needle

– Now perform the following measurements to determine the degree

of wear:

Outer rotor - oil pump housing: max. 0.20 mm

Outer rotor - inner rotor: max. 0.20 mm

– Fill the oil pump housing with oil and mount the oil pump cover.
– Apply Loctite 243 to the thread of screw

and mount the screw.

CAUTION

ILL OIL PUMPS WITH OIL BEFORE PREASSEMBLING

5-14D

150

LOCTITE 243

150

LOCTITE 243

Oil lines (SX, SXC)

– Check oil lines and banjo bolts for damage and clear passage.
– When repairing the engine, the microfilter

and the oil filter

must be replaced.

Oil lines (SC)

– Check oil lines and banjo bolts for damage and clear passage.
– When repairing the engine, the microfilter

and the oil filter

must be replaced.

Repair manual KTM LC4

Art.-Nr

. 3.206.006 -E

5-15D

Oil lines (660 SMC)

– Check oil lines and banjo bolts for damage and clear passage.
– When repairing the engine, the microfilter

and the oil filter

must be replaced.

Oil lines (Models with frame oil)

– Check oil lines and banjo bolts for damage and clear passage.
– When repairing the engine, the fine filter

and the oil filter

must be replaced.

LOCTITE 243

150

LOCTITE 243

LOCTITE 243

5-16D

Checking the kickstarter components for wear

Starter gear

Check the bearing for clearance (the starter gear must be in permanent
mesh with the outer clutch hub).

Intermediate starter gear

Check the bearing for clearance.

Kick starter shaft

Check the toothing for signs of wear.

Ratchet gear

Check the ascending surface and the toothing for signs of wear.

Stop bolt

Check for signs of wear.

Replace the seal ring

NOTE: Due to a parts change from 2000 onwards the seal ring is
blue-green and is to be mounted with the seal lip to the outer side.

Preassembly of kickstarter shaft

– Clamp kickstarter shaft with toothed end in vice (use soft jaw-

covers).

– Mount circlip

in lower ring groove.

– Fit spring guide

with collar facing downwards and circlip

with

sharp edge facing upwards.

– Remove kickstarter shaft from vice and fit ratchet gear spring.
– Mount the ratchet gear

on the kickstarter shaft in such a way that

the markings

and

coincide.

Clutch cover

Balancer shaft bearing

Use the bearing extractor tool with insert to remove the grooved ball
bearing from the bearing seat.
Insert the new bearing into the seat and ensure flush fit.

Seal ring

Use a screwdriver to lever the old shaft seal ring out of the clutch cover.
Insert the new shaft seal ring and ensure flush fit.

Replacing absorbing elements of the outer clutch hub

– Drill open the clutch rivets

in area of the retaining bracket

and

take off the parts.

NOTE: When performing repair work always exchange all 8 absorbing
elements.

CAUTION

HE DAMPING ELEMENTS ARE WIDER THAN THE PRIMARY GEAR CROWN

. T

ENSURE THAT THE OUTER CLUTCH HUB AND RETAINING BRACKET ARE POSITIONED
DIRECTLY ON THE PRIMARY GEAR CROWN

THE PARTS MUST BE HELD IN POSITION

UNDER TENSION WITH THE CLUTCH RIVETTING TOOL

BEFORE RIVETTING

– Apply the special tool as shown, screw together and lock the rivets

with a pointed mandrel and a round mandrel.

Locking pressure for the pointed mandrel: approx. 4000 kg

Locking pressure for the round mandrel: approx. 5000 kg

Repair manual KTM LC4

Art.-Nr

. 3.206.006 -E

Checking the clutch components for wear

Thrust bearing

– Check for signs of wear.

Push rod

– Check the face side for signs of wear.

Clutch release shaft

, sealing cup

and needle bearing

– Check for damage and signs of wear.

Clutch pressure springs

– Minimum length: 34.5 mm (1.36 in) (length/new spring: 37 mm (1.457 in)).

Replace all 6 springs if necessary.

Clutch discs

– Clutch discs must be plane.

7 steel discs

≠ 1.5 mm (0.066 in) must be free of grooves.

8 lining discs ≠ 2.7 mm (0.106 in), wear limit: 2.5 mm (0.1 in)

Inner clutch hub

– Check both the exterior and the interior toothing for signs of wear.

Needle bearing

– Check for signs of wear.

Outer clutch hub

– Check if all rivets

are tight.

Absorbing elements

Power transmission from the primary drive to the clutch is cushioned by rubber elements

. These rubber elements must be

checked in the course of normal checking for signs of wear. It is recommended to check the elements while disassembling the
engine. Try to turn the outer clutch hub after removing the inner clutch hub (engine will lock). Dead travel should be impossible.

Check O-ring

for brittleness and cracks. If the cross section of the O-ring is oval (deformed) replace the O-ring.

5-17D

LOCTITE 243

From model 2003 on

5-18D

Checking the shift mechanism components for
wear

Shift forks

Check the fork leaf for signs of wear.
Check the shift roller driving pin

for signs of wear.

Shift rolls

Check the shift rolls for hairline cracks and pressure marks.
Additionally, make sure that the shift rolls turn easily on the
driving pins

of the shift forks.

Shift roller

Check the shift grooves for signs of wear.
Check the two grooved ball bearings of the shift roller for
wear.

Slide plate

Check the contact surfaces for signs of wear.
Check the return surface of the slide plate for signs of wear
(replace in the case of deep grooves).

Slide guides
Check clearance (maximum clearance between guide bolt
and slider 0.70 mm / 0.027 in.).

Guide bolt

Check for tight fit and signs of wear.

Preassembly of shift shaft

– Push steel disc

(14x28x2 mm) onto shift shaft.

– Mount the return spring

, positioning the offset

on the side of

the shift quadrant.

– Mount spring sleeve

with shallower collar facing shift quadrant.

– Cross return spring legs and hook in shift quadrant.
– Grease and mount both O-rings

Content .. 5 6 7 8 ..