KTM LC4 400-660LC42003 engine. Manual - part 3

2-13D

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 screws 

1

and cover 

2

together

with the rubber boot 

3

. The oil level in the horizontal-standing

master cylinder should be 4 mm below the upper edge. 
If necessary, fill up with biodegradable hydraulic oil SAE 10 (f.ex.
Motorex Kupplungs-Fluid 75).

!

CAUTION

!

– KTM 

USES BIODEGRADABLE HYDRAULIC OIL FOR THE HYDRAULIC CLUTCH

CONTROL

. N

EVER MIX BIODEGRADABLE HYDRAULIC OILS WITH MINERAL OILS

.

– A

LWAYS USE BIODEGRADABLE HYDRAULIC OIL

SAE 10 

TO FILL UP THE MASTER

CYLINDER

. N

EVER REFILL WITH MINERAL HYDRAULIC OIL OR BRAKE FLUID

.

Bleeding of the hydraulic clutch

To  bleed, the cover of the master cylinder of the clutch needs to be
removed. For this purpose, remove screws 

1

and take off cover 

2

together with rubber bellows 

3

. At the slave cylinder of the clutch,

remove the bleeder nipple 

4

. In its place, mount the bleeder syringe 

5

which is filled with SAE 10 hydraulic oil. Refill oil until oil is discharged
from the bore 

6

of the master cylinder in a bubble-free state. Make

sure that the oil does not overflow. The bleeder syringe can be
purchased from your KTM dealer. 

Having completed the bleeding procedure, you have to verify that the
oil level in the master cylinder is correct. If necessary, fill up with
biodegradable hydraulic oil SAE 10 (f.ex. Motorex Kupplungs-Fluid
75). 

!

CAUTION

!

– KTM 

USES BIODEGRADABLE HYDRAULIC OIL FOR THE HYDRAULIC CLUTCH

CONTROL

. N

EVER MIX BIODEGRADABLE HYDRAULIC OILS WITH MINERAL OILS

.

– A

LWAYS USE BIODEGRADABLE HYDRAULIC OIL

SAE 10 

TO FILL UP THE MASTER

CYLINDER

. N

EVER REFILL WITH MINERAL HYDRAULIC OIL OR BRAKE FLUID

.

2

1

3

4

6

5

Repair manual  KTM LC4 

Art.-Nr

.  3.206.006 -E

Removing the engine

– Thoroughly clean the entire motorcycle.
– When working on a motorcycle with engine guard, remove the

latter.

– Jack the motorcycle up on a stable supporting device.
– Remove the seat, the side covers as well as the tank and the spoilers.
– Disconnect the negative pole of the battery.

– Undo the 2 hose clamps 

1

as well as hose clamp 

2

. Pull the

carburetor backwards out of the intake flange and swing it aside.

– Unhook the 4 springs 

3

at the exhaust manifold.

– Undo bolt 

4

.

– Undo bolt 

5

and remove the exhaust manifold.

– Disconnect water hoses 

6

and 

7

from the water pump and let out

the cooling liquid.

– Remove the two bolts 

8

, disconnect and remove the fan.

– Unhook the clutch cable and the decompression cable.
– Disconnect the bleeder hose at the valve cover.

3-2D

1

2

3

4

5

7

8

6

– Remove the two bolts 

1

and take off the chain guard.

– Remove the chain damping plate 

6

.

– Remove the chain joint and take off the chain.

From model 2003 on:
– Remove the 3 bolts 

3

of the clutch slave cylinder and pull the clutch

slave cylinder off the casing.

– Disconnect the bleeder hose 

4

.

– Disconnect the positive cable 

5

from the electric starter motor.

– Disconnect all electric plug and socket connections from the engine.
– Remove the banjo bolt 

6

.

– Disconnect the water hose 

7

.

3-3D

1

1

2

3

3

4

5

6

7

Repair manual  KTM LC4 

Art.-Nr

.  3.206.006 -E

– Remove the jet screw 

1

.

– Remove the left as well as the right engine retaining bracket 

2

.

– Remove bolt 

3

as well as the swingarm pivot 

4

.

– Then lift the engine out of the frame.

Installing the engine

NOTE: To install the engine reverse the procedure indicated above.

– When working on a model with an engine guard keep in mind that

opening 

A

must be located on the right side and face the engine.

Tightening torques: 

Swingarm pivot:

100 Nm

74 ft.lb

Engine mounting bolts M8:

40 Nm

30 ft.lb

Engine mounting bolts  M10:

70 Nm

50 ft.lb

Banjo bolt (oil pipe on the frame):

15 Nm

11 ft.lb

Jet screw (clutch cover):

10 Nm

7 ft.lb

All other M6 bolts:

10 Nm

7 ft.lb

All other M8 bolts:

25 Nm

19 ft.lb

All other M10 bolts:

45 Nm

33 ft.lb

NOTE: Use only high-quality antifreeze (e.g. Shell Advance Coolant) for
the cooling system. The frame oil should always be changed after
engine repair.

! 

CAUTION

!

A

FTER INSTALLING THE ENGINE CAREFULLY BLEED THE OIL SYSTEM

(

SEE OIL CHANGE

INSTRUCTIONS

). D

O NOT REV THE ENGINE DURING THE BLEEDING PROCESS

!

– The motorcycle can be tested as soon as the engine is running

smoothly. After the test run check and, if necessary, correct all liquid
levels.

3-4D

1

2

3

4

A

DRAIN ENGINE OIL  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2

REMOVING THE ELECTRIC STARTER MOTOR  . . . . . . . . . . . . . . . . . . . . .4-2

REMOVING THE CLUTCH RELEASE LEVER AND THE OIL HOSES  . . . . . . .4-3

REMOVING THE OIL FILTER  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3

REMOVING THE EPC WIRING HARNESS . . . . . . . . . . . . . . . . . . . . . . . . . .4-3

REMOVING THE IGNITION (KOKUSAN 4K-2)  . . . . . . . . . . . . . . . . . . . . . .4-3

REMOVING THE IGNITION (SEM)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-5

REMOVING THE IGNITION (KOKUSAN 4K-3)  . . . . . . . . . . . . . . . . . . . . . .4-5

REMOVING THE ELECTRIC STARTER DRIVE  . . . . . . . . . . . . . . . . . . . . . . .4-6

REMOVING THE CYLINDER HEAD TOP SECTION  . . . . . . . . . . . . . . . . . . .4-7

BLOCKING THE CRANKSHAFT  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-8

REMOVING THE CAMSHAFT AND THE AUTOMATIC TENSIONER  . . . . . .4-8

REMOVING CYLINDER HEAD  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-10

REMOVING CYLINDER AND PISTON  . . . . . . . . . . . . . . . . . . . . . . . . . . .4-10

REMOVING ENGINE SPROCKET  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-11

REMOVING CLUTCH AND PRIMARY DRIVE  . . . . . . . . . . . . . . . . . . . . . .4-11

REMOVING THE OIL PUMPS  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-13

REMOVING THE TIMING CHAIN AND THE TIMING GEAR  . . . . . . . . . . .4-14

REMOVING THE CLUTCH RELEASE SHAFT  . . . . . . . . . . . . . . . . . . . . . . .4-14

PARTING OF ENGINE HOUSING  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-15

REMOVING THE SHIFT MECHANISM  . . . . . . . . . . . . . . . . . . . . . . . . . . .4-15

REMOVING THE TRANSMISSION SHAFTS  . . . . . . . . . . . . . . . . . . . . . . .4-17

REMOVING THE KICKSTARTER SHAFT  . . . . . . . . . . . . . . . . . . . . . . . . . .4-17

Repair manual  KTM LC4 

Art.-Nr

.  3.206.006 -E

DISASSEMBLING THE ENGINE

INDEX

4-1D

4

Repair manual  KTM LC4 

Art.-Nr

.  3.206.006 -E

4-2D

– Fit engine to engine work stand.

– Remove bolt 

1

together with the washers. Then remove the shift

lever together with the V-seal ring behind.

– Remove bolt 

2

together with the washer. Then remove the 

kickstarter.

– Remove spark plug

Drain engine oil

– Remove oil drain plug 

3

and magnetic plug 

4

and drain oil.

Removing the electric starter motor

– Undo 2 bolts 

5

and remove the electric starter motor from the

flange.

1

2

5

up to model 2001

from modell 2002 on

3

3

4

4

4-3D

Removing the clutch release lever and the oil hoses

– Undo bolt 

1

and remove the clutch release lever.

– Remove the two banjo bolts 

2

together with the seal rings and

remove both oil hoses.

Removing the oil filter

– Remove all three bolts 

3

and take off the oil filter cover together

with the O-ring or gasket.

– Take the oil filter out of the engine housing.

Removing the EPC wiring harness

– Undo the 3 bolts 

4

and remove the EPC wiring harness.

Removing the ignition (Kokusan 4K-2)

– Undo 4 bolts and remove the ignition cover with the stator incl.

gasket.

1

2

2

3

4

4