KTM LC4 400-660LC42003 engine. Manual - part 12

Repair manual  KTM LC4 

Art.-Nr

.  3.206.006 -E

ELECTRICAL – SC ‘99  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-31
CHECKING THE VOLTAGE REGULATOR  . . . . . . . . . . . . . . . . . . . . . . . . .7-31

CHECKING THE CAPACITOR  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-31

CHECKING THE IGNITION COIL  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-31

ELECTRICAL – DUKE ‘99  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-32
CHARGING SYSTEM  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-32

LEAKAGE INSPECTION  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-32

CHARGING VOLTAGE / CHECKING THE VOLTAGE REGULATOR  . . . . . . .7-33

REMOVING THE BATTERY  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-33

CHARGING THE BATTERY  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-33

CHECKING THE CAPACITOR  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-34

ELECTRIC STARTER SYSTEM  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-35

CHECKING THE START AUXILIARY RELAY . . . . . . . . . . . . . . . . . . . . . . . .7-36

CHECKING THE AUXILIARY STARTING RELAY FOR FAULTLESS OPERATION . . .7-36

CHECKING THE DIODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-37

CHECKING THE CLUTCH SWITCH  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-37

CHECKING THE EMERGENCY OFF SWITCH  . . . . . . . . . . . . . . . . . . . . . .7-37

CHECKING THE STARTER RELAY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-38

CHECKING THE ELECTRIC STARTER MOTOR  . . . . . . . . . . . . . . . . . . . . .7-38

TROUBLE SHOOTING IN THE ELECTRIC STARTER SYTEM . . . . . . . . . . . .7-38

CHECKING THE IDLE SWITCH  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-38

IGNITION SYSTEM  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-39

CDI UNIT  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-40

CHECKING THE IGNITION COIL  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-40

SPARK PLUG CONNECTOR  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-40

CHECKING THE SIDE STAND RELAY  . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-40

CHECKING THE SIDE STAND SWITCH . . . . . . . . . . . . . . . . . . . . . . . . . . .7-41

TROUBLE SHOOTING IN THE IGNITION SYSTEM  . . . . . . . . . . . . . . . . . .7-41

MEASUREMENTS WITH PEAK VOLTAGE ADAPTER
(FROM MODEL 2000 ON)

DYNAMIC GENERATOR VALUES

400/640 LC4-E, 625 SXC, DUKE, ADVENTURE  . . .7-42

STATIC IGNITION VALUES 400/640 LC4-E

, 625 SXC, DUKE, ADVENTURE  . . .7-43

STATIC GENERATOR VALUES

400/640 LC4-E, 625 SXC, DUKE, ADVENTURE  . . .7-45

STATIC IGNITION VALUES

400/620/625 SC, 660 SMC  . . . . . . . . . . . . . . . .7-47

STATIC GENERATOR VALUES

400/620/625 SC, 660 SMC  . . . . . . . . . . . . . .7-49

CHECKING SPEEDOMETER AND SPEEDOMETER SENSOR  . . . . . . . . . . . .7-51

INDEX

7-3D

Repair manual  KTM LC4 

7-4D

Art Nr  320549-D           

Checking the voltage regulator-rectifier

– Start the engine and switch on the low beam.
– Connect a voltmeter to the two terminals of the capacitor (red/white

cable = positive, brown cable = negative).

– Accelerate the engine to a speed of 5000 r.p.m. and read off the

voltage.

Nominal value: 14.0 - 15.0 V

If the reading significantly deviates from the nominal value above,
check the capacitor. If the capacitor is intact, replace the voltage
regulator-rectifier.

Checking the voltage regulator

The two voltage regulators are located under the right side cover at the
air filter box.
The voltage regulators are connected downstream of the switches. One
of the voltage regulators regulates only the brake light circuit, the other
regulates the circuit for the head light, the tail light, the speedometer
illumination and the horn.

A defect voltage regulator can cause different kinds of trouble:

● No voltage in the circuit
In this case, the voltage regulator must be disconnected at idle speed.
The voltage regulator is defect if the power consumers now work
properly.
If the power consumers are still not supplied with power, the switch, the
wiring harness or the ignition system must be checked for defects.

● Excessive voltage in the circuit
The bulbs burn out.
Connect a voltmeter (yellow cable = positive, brown cable = negative)
to check the voltage. Start the engine and switch on the power
consumers.

At an engine speed of 3000 r.p.m, the voltage regulator must supply a
voltage of 12.0 - 14.0 V A.C. At higher engine speeds, the limit of 14 V
should not be exceeded either.

If the reading significantly deviates from the nominal value, replace the
voltage regulator.

Checking the capacitor

– Discharge the capacitor 1 by bridging the two terminals with a

screwdriver and remove.

– Connect the negative pole of a 12V battery with the negative

terminal of the capacitor. The connection between the positive pole
of the battery and the positive terminal of the capacitor (marked +)
is made with a test lamp 

1

. 

– When the power circuit is closed, the test lamp must begin to light

up. As capacitor charging increases, the brightness of the test lamp
must decrease.

– The test lamp must go out after 0,5-2 seconds (depending on the

lamp capacity).

– If the test lamp does not go out or does not light up at all, the

capacitor is faulty.

! 

CAUTION

!

D

ISCHARGE THE CAPACITOR BEFORE AND AFTER EACH TEST

.

W

HEN

INSTALLING

THE

CAPACITOR

, 

MAKE

SURE

THAT

THE

TERMINALS

ARE

CONNECTED IN ACCORDANCE WITH THEIR MARKINGS

. C

ONNECT RED

/

WHITE CABLE

TO

+ 

TERMINAL

.

1

ELECTRICAL – SUPER COMPETITION

7-5D

ELECTRICAL – LC4 COMPETITION

bl  . . . . . . . . .blue
br  . . . . . . . . .brown
ge  . . . . . . . .yellow
gr  . . . . . . . . .grey
g   .  . . . . . . . .green
o  . . . . . . . . .orange
r   .  . . . . . . . . .red
ra  . . . . . . . . .pink
s . . . . . . . . . .black
v  . . . . . . . . .violet
w  . . . . . . . . .white

Charging system

1

Generator

2

Regulator-rectifier

3

Main fuse (20 A)

4

Battery (12V / 8 Ah)

5

Capacitor

Leakage inspection

The drop test must be performed before checking the voltage
regulator/rectifier
– Turn off the ignition and disconnect the ground wire from the

battery.

– Insert an amperemeter between the ground wire and the negative

pole of the battery.

Setpoint value: max. 1 mA

– Check for power consumers, should the measured value exceed the

indicated maximum value.

Example:

● defective voltage regulator-rectifier

● leak currents in the socket connectors, in the ignition lock or in the

starter relay.

0,00

2

4

3

5

1

ignition

lock

ge-r

br

bl

ge

Repair manual  KTM LC4 

Art.-Nr

.  3.206.006 -E

7-6D

Removing the battery

– Remove the seat.
– Disconnect first the negative and then the positive pole of the

battery.

– Remove the bolts 

1

and swing the battery support with the voltage

regulator-rectifier sideways.

– Remove the battery.
– When reinstalling the battery, connect the negative pole last.

! 

CAUTION

!

F

OLLOW THE INSTRUCTIONS OF THE MANUFACTURER WHEN FILLING A NEW BATTERY

. 

T

HE RELEVANT SAFETY INSTRUCTIONS ARE ALSO CONTAINED IN THE USER MANUAL

SUPPLIED WITH THE BATTERY

.

Charging the battery

– Remove the battery and check the charging level. Use a voltmeter to

measure the voltage between the battery poles (off-load voltage).

– Accurate results can only be obtained if the battery has neither been

charged nor discharged during a period of 30 minutes preceding the
measuring.

– If the battery is empty, it can be recharged for a maximum period of

10 hours at 0.8 A and a maximum of 14.4 V.

! 

CAUTION

!

– T

O AVOID DAMAGE

, 

DO NOT REMOVE THE LOCKING BAR

– A

LWAYS CONNECT THE BATTERY TO THE CHARGING UNIT BEFORE TURNING THE

CHARGING UNIT ON

.

– W

HEN RECHARGING THE BATTERY IN CLOSED ROOMS ENSURE SUFFICIENT

VENTILATION

. E

XPLOSIVE GASES ARE RELEASED DURING THE BATTERY CHARGING

PROCESS

.

– C

HARGING TIME AND CHARGING VOLTAGE SHOULD NOT EXCEED THE STATED

VALUES

. O

THERWISE ELECTROLYTE WILL BE RELEASED THROUGH THE SAFETY

VALVES

.

– A

VOID QUICK CHARGING IF POSSIBLE

.

Charging voltage / checking the voltage regulator-rectifier

NOTE: The values stated below apply only to fully charged batteries
(minimum charging level 90%).

– Start the engine and switch on the low beam.
– Connect a voltmeter to both battery connections.
– Accelerate the engine to a speed of 5000 rpm and read off the

voltage.

Nominal value: 14.0 - 15.0 V

In the case of a significant deviation from the nominal value:
– Check the connector between the stator and the voltage regulator-

rectifier and the connector between the voltage regulator-rectifier
and the cable tree.

– Check the stator.
– Replace the voltage regulator-rectifier.

1

off load voltage

charging level

charging time   charging voltage

Volt

%

0.8 A

>12.7

100

––

~12.5

75

4 h

max.

~12.2

50

7 h

14.4 V

~12.0

25

11 h

~11.8

0

14 h

7-7D

Checking the capacitor

– Pull main fuse out of the fuse holder.
– Discharge the capacitor 1 by bridging the two terminals with a

screwdriver and remove.

– Connect the negative pole of a 12V battery with the negative

terminal of the capacitor. The connection between the positive pole
of the battery and the positive terminal of the capacitor (marked +)
is made with a test lamp 

3

.

– When the power circuit is closed, the test lamp must begin to light

up. As capacitor charging increases, the brightness of the test lamp
must decrease.

– The test lamp must go out after 0,5-2 seconds (depending on the

lamp capacity).

– If the test lamp does not go out or does not light up at all, the

capacitor is faulty.

! 

CAUTION

!

D

ISCHARGE THE CAPACITOR BEFORE AND AFTER EACH TEST

.

W

HEN

INSTALLING

THE

CAPACITOR

, 

MAKE

SURE

THAT

THE

TERMINALS

ARE

CONNECTED IN ACCORDANCE WITH THEIR MARKINGS

. C

ONNECT RED

/

WHITE CABLE

TO

+ 

TERMINAL

.

Checking the neutral switch

– Remove the chain cover.
– Connect one terminal of a test lamp to the positive pole of the

battery and the other to connection 

1

of the neutral switch.

– The test lamp must light up when the transmission is switched to

neutral.

– The test lamp must go out as soon as a gear is put in.

3

1

Repair manual  KTM LC4 

Art.-Nr

.  3.206.006 -E

7-8D

ELECTRICAL – LC4

bl  . . . . . . . . .blue
br  . . . . . . . . .brown
ge  . . . . . . . .yellow
gr  . . . . . . . . .grey
g   .  . . . . . . . .green
o  . . . . . . . . .orange
r   .  . . . . . . . . .red
ra  . . . . . . . . .pink
s . . . . . . . . . .black
v  . . . . . . . . .violet
w  . . . . . . . . .white

Charging system

1

Generator

2

Regulator-rectifier

3

Main fuse (20 A)

4

Battery (12V / 8 Ah)

5

Capacitor

Leakage inspection

The drop test must be performed before checking the voltage
regulator/rectifier
– Turn off the ignition and disconnect the ground wire from the

battery.

– Insert an amperemeter between the ground wire and the negative

pole of the battery.

Setpoint value: max. 1 mA

– Check for power consumers, should the measured value exceed the

indicated maximum value.
Example:

● defective voltage regulator-rectifier

● leak currents in the socket connectors, in the ignition lock or in the

starter relay.

0,00

2

4

3

5

ignition

lock

start

relay

CDI

ge-r

br

s-r

ge

r-s

7-9D

Removing the battery

– Remove the seat.
– Disconnect first the negative and then the positive pole of the

battery.

– Remove the bolts 

1

and swing the battery support with the voltage

regulator-rectifier sideways.

– Remove the battery.
– When reinstalling the battery, connect the negative pole last.

! 

CAUTION

!

F

OLLOW THE INSTRUCTIONS OF THE MANUFACTURER WHEN FILLING A NEW BATTERY

. 

T

HE RELEVANT SAFETY INSTRUCTIONS ARE ALSO CONTAINED IN THE USER MANUAL

SUPPLIED WITH THE BATTERY

. A

NY FAILURE TO OBSERVE THESE INSTRUCTIONS MAY

RESULT IN SEVERE INJURIES

.

Charging the battery

– Remove the battery and check the charging level. Use a voltmeter to

measure the voltage between the battery poles (off-load voltage).

– Accurate results can only be obtained if the battery has neither been

charged nor discharged during a period of 30 minutes preceding the
measuring.

– If the battery is empty, it can be recharged for a maximum period of

10 hours at 0.8 A and a maximum of 14.4 V.

! 

CAUTION

!

– T

O AVOID DAMAGE

, 

DO NOT REMOVE THE LOCKING BAR

.

– A

LWAYS CONNECT THE BATTERY TO THE CHARGING UNIT BEFORE TURNING THE

CHARGING UNIT ON

.

– W

HEN RECHARGING THE BATTERY IN CLOSED ROOMS ENSURE SUFFICIENT

VENTILATION

. E

XPLOSIVE GASES ARE RELEASED DURING THE BATTERY CHARGING

PROCESS

.

– C

HARGING TIME AND CHARGING VOLTAGE SHOULD NOT EXCEED THE STATED

VALUES

. O

THERWISE ELECTROLYTE WILL BE RELEASED THROUGH THE SAFETY

VALVES

.

– A

VOID QUICK CHARGING IF POSSIBLE

.

Charging voltage / checking the voltage regulator-rectifier

NOTE: The values stated below apply only to fully charged batteries
(minimum charging level 90%).

– Start the engine and switch on the low beam.
– Connect a voltmeter to both battery connections.
– Accelerate the engine to a speed of 5000 rpm and read off the

voltage.

Nominal value: 14.0 - 15.0 V

In the case of a significant deviation from the nominal value:
– Check the connector between the stator and the voltage regulator-

rectifier and the connector between the voltage regulator-rectifier
and the cable tree.

– Check the stator.
– Replace the voltage regulator-rectifier.

1

off load voltage

charging level

charging time   charging voltage

Volt

%

0.8 A

>12.7

100

––

~12.5

75

4 h

max.

~12.2

50

7 h

14.4 V

~12.0

25

11 h

~11.8

0

14 h

Repair manual  KTM LC4 

Art.-Nr

.  3.206.006 -E

7-10D

Checking the capacitor

– Pull main fuse out of the fuse holder.
– Discharge the capacitor 1 by bridging the two terminals with a

screwdriver and remove.

– Connect the negative pole of a 12V battery with the negative

terminal of the capacitor. The connection between the positive pole
of the battery and the positive terminal of the capacitor (marked +)
is made with a test lamp 

1

.

– When the power circuit is closed, the test lamp must begin to light

up. As capacitor charging increases, the brightness of the test lamp
must decrease.

– The test lamp must go out after 0,5-2 seconds (depending on the

lamp capacity).

– If the test lamp does not go out or does not light up at all, the

capacitor is faulty.

! 

CAUTION

!

D

ISCHARGE THE CAPACITOR BEFORE AND AFTER EACH TEST

.

W

HEN

INSTALLING

THE

CAPACITOR

, 

MAKE

SURE

THAT

THE

TERMINALS

ARE

CONNECTED IN ACCORDANCE WITH THEIR MARKINGS

. C

ONNECT RED

/

WHITE CABLE

TO

+ 

TERMINAL

.

1