KTM 400-660 LC4 1998-2005 Operating instructions

400-660 LC4
REPARATURANLEITUNG
MANUALE DI RIPARAZIONE
MANUEL DE RÉPARATION
MANUAL DE REPARACIÓN
Art.Nr.: 3.206.024-E
REPAIRMANUAL1998-2005

REPAIRMANUAL1998-2005 400-660 LC4
KTM Group Partner

1SERVICE-INFORMATIONS
2GENERAL INFORMATION
3REMOVING AND REFITTING ENGINE
4DISASSEMBLING THE ENGINE
5 SERVICING ON INDIVIDUAL COMPONENTS
6ASSEMBLING THE ENGINE
7 ELECTRICAL
8FUEL SYSTEM
9TROUBLE SHOOTING
10 CHASSIS
11 TECHNICAL SPECIFICATIONS
12 PERIODIC MAINTENANCE SCHEDULE
13 WIRING DIAGRAMS
14
15
16

Remove page (s) Replace by page (s) Insert page (s) after page
2-13 2-13F
4-8 4-8F
5-7 5-7F
5-16 5-16F
5-23 5-23F
6-6 6-6F
6-8 to 6-9 6-8F to 6-9F
6-15 6-15F
6-19 6-19F
10-1 10-1F
10-3 10-3F
10-5 to 10-7 10-5F to 10-7F
10-9F 10-8
11-2 11-2F to 11-2Fb
11-67 to 11-69 11-67F to 11-77F
12-1Fb 12-1
12-38F to 12-47F 12-37
13-2F to 13-2Fd 13-1
13-63 to 13-64 13-63F to 13-134F
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:
1,3,7,9,28,49,65,74,81,93,95,96,102,106,225,228,230-232,234,237,238,
303-313,316,354-363,366-369,430-501
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.

Repair manual KTM LC4 Art.-Nr. 3.206.024 -E
3.205.49-E Repair Manual LC4 6/1998
Basic version 1998 model year
(Engine number with first digit “8“)
3.205.73-E Update of Rep.Manual LC4 7/1999
Model year 1999
(Engine number with first digit “9“)
3.205.89-E Update of Rep.Manual LC4 9/2000
Model year 2000/2001
(Engine number with first digit “0“ and “1“)
3.210.30-E Update of Rep.Manual LC4 12/2001
Model year 2002
(Engine number with first digit “2“)
3.206.006-E Update of Rep.Manual LC4 4/2003
Model year 2003
(Engine number with first digit “3“)
3.206.014-E Update of Rep.Manual LC4 11/2003
Model year 2004
(Engine number with first digit “4“)
3.206.024-E Update of Rep.Manual LC4 03/2005
Model year 2005
(Engine number with first digit “5“)
Modification / Update:
technical details model 2005, special tools chassis,
cutting and riveting the chain
technical data, maintenance schedules and wiring diagrams for 2005
LEGENDE - UPDATE
Stand: 03/2005

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.
In accordance with the international quality management ISO 9001 standard, KTM uses
quality assurance processes that lead to the highest possible product quality.
KTM Sportmotorcycle AG reserves the right to modify any equipment, technical specifications,
colors, materials, services offered and rendered, and the like so as to adapt them to local conditions
without previous announcement and without giving reasons, or to cancel any of the above items
without substituting them with others. It shall be acceptable to stop manufacturing a certain model
without previous announcement.
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

MODELS WITHOUT FRAME OIL
CHANGING THE ENGINE OIL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
CHANGING THE OIL FILTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
CHANGING THE MICROFILTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3
OIL CIRCUIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4
OIL CIRCUIT 660 SMC (model 2003) . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
MODELS WITH FRAME OIL
CHANGING THE ENGINE OIL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6
CHANGING THE FINE SCREEN FILTER . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6
CHANGING THE OIL FILTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-7
OIL CIRCUIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8
OIL CIRCUIT 660 SMC (from model 2004 on) . . . . . . . . . . . . . . . . . . . . . .2-9
SECONDARY AIR SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-10
EPC-SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-12
SPECIAL TOOLS CHASSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13
SPECIAL TOOLS MOTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-14
BLEEDING OF THE HYDRAULIC CLUTCH . . . . . . . . . . . . . . . . . . . . . . . .2-16
Repair manual KTM LC4 Art.-Nr. 3.206.014 -E
GENERAL INFORMATION
INDEX
2-1E
2

Repair manual KTM LC4 Art.-Nr. 3.206.014 -E
2-2E
Changing the engine oil (models without frame oil)
NOTE: The engine oil change is to be carried out when the engine is
still warm.
 WARNING 
ANENGINE HAVING BEEN RUN WARM, AND THE ENGINE OIL IN IT ARE VERY HOT -
DO NOT BURN YOURSELF
.
–Place the motorbike on a horizontal surface. Remove the two plugs
(1and 2), and drain oil into a container.
NOTE: A third plug was installed in the 660 SMC model. Tightening
torque: 20 Nm
! CAUTION !
THE SCREW PLUG AMUST NOT BE REMOVED, THIS IS PART OF THE BY-PASS VALVE.
–Clean the plugs thoroughly with a fireproof solvent and compressed
air, in order to remove the metal abrasion.
–After all the oil has drained through, clean raised and flat faces and
install plugs with seals. Tighten plug 1with 30 Nm and plug 2with
20 Nm.
–Remove the oil dipstick at the clutch cover, pour in engine oil and
replace the oil dipstick.
Oil capacity (up to model 2002) : 1.40 l
Oil capacity (from model 2003 on) : 1.50 l
Changing the oil filter
Replace the oil filter when changing the engine oil.
–Press the foot brake pedal and place a screwdriver or similar between
foot brake pedal and stopper roll so that the oil filter cover is more
accessible.
–Remove banjo bolt 3and the three bolts 4.
–Remove oil filter cover 5 and oil filter.
–Clean filter housing, oil filter cover and sealing surfaces. Check oil
duct in oil filter cover if clogged.
–Press the new O-ring 6into the groove of the filter cover (if
necessary fix with grease). Mount a new oil filter 7on the
connection piece of the oil filter cover an mount the whole unit.
NOTE: From model 2001 onwards the gasket 8is mounted with a
changed filter cover 5. If the new gasket 8should be used on older
engines, the filter cover must be flat regrinded or renewed (see
Technical Info Nr. 0201/30/01).
–Mount three bolts and tighten with 5 Nm.
–Mount hollow bolt with seal rings and tighten with 15 Nm.
1
1
AA
2
up to Modell 2001 from Modell 2002 on
2
3
4
56
7
8
3
4
5

2-3E
Changing the microfilter
Replace the microfilter while changing the engine oil.
–To do so, remove bolts 1and take off the microfilter cover 2.
–Remove the microfilter, clean its parts and check the O-ring on the
microfilter cover for signs of damage.
–Insert a new microfilter into the filter housing, tilt the motorcycle
sideways and fill the microfilter housing with engine oil.
–Slightly grease the O-ring and mount the microfilter cover. Then put
the motorcycle back on its stand.
–It is necessary to bleed the microfilter so that all lubricating points
can be quickly supplied with engine oil.
–To do this, fill with oil and remove the jet screw from the oil line on
the clutch cover.
–Start the engine and close off the bore on the clutch cover with a
rag.
–Allow the engine to run at idle until oil runs out of the oil line 3.
–Turn off the engine. Mount the jet screw, using two new seal rings.
–Torque the jet screw to 10 Nm and check for leaks.
–Start the engine and let it idle for 1 - 2 minutes.
!
CAUTION
!
DONOT REV UP THE ENGINE IMMEDIATELY AFTER AN OIL CHANGE ! KEEP IN MIND
THAT IT TAKES SOME TIME UNTIL ALL LUBRICATING POINTS ARE PROPERLY PROVIDED
WITH ENGINE OIL.
–Allow the engine to run until warm. Then, turn off the engine, and
place the motorbike on a flat, level surface in an upright position
(center stand). Wait for 5 minutes. Unscrew and remove the oil
dipstick, and wipe it clean with a cloth.
–Screw the dipstick in all the way and remove it again. The oil level
should be between the two marks on the oil dipstick, however, it
must never rise above the MAX mark. Otherwise, engine oil would
get into the air filter box by way of the engine venting system. Add
engine oil, if necessary.
–Finally, check oil system and engine for leaks.
! CAUTION !
–ONLY USE HIGH-QUALITY OILS MEETING OR SURPASSING THE QUALITY
REQUIREMENTS OF JASO T903 MA (FOR SPECIFICATIONS SEE CONTAINERS).
–I
NSUFFICIENT OIL OR POOR QUALITY OIL RESULTS IN PREMATURE WEAR OF THE
ENGINE.
–Y
OU MAY USE EITHER MINERAL OILS OR SYNTHETIC OILS FULFILLING THE ABOVE
CRITERIA.
NOTE: Dispose of used oil properly !
Under no circumstances may used oil be disposed of in the sewage
system or in the open countryside.
1 liter oil contaminates 1.000.000 liter water.
3
1
1
2
0°C
32°F
10W/50
5W/40
JASO T903 MA
TEMPERATURE

2-4E
Repair manual KTM LC4 Art.-Nr. 3.206.014 -E
8
7
1
2
3
4
5
6
9
10 11
Oil circuit
The oil pump 1pumps the engine oil past the by-pass valve 2through the oil filter 3. After the oil filter, an oil lead branches
off to a jet 4which sprays engine oil onto the piston pin bearing and piston head. The second oil lead takes the main flow of oil
to the microfilter 5, which filters out even the finest impurities. The cleaned engine oil is pumped through the oil lead and the
clutch cover into the crankshaft to the connecting rod bearing 6and drips into the crankcase. An additional oil pump 7sucks
the engine oil out of the crankcase and pumps it through the oil line 8to the gear wheels of the 4th and 5th gear. Via the gear
wheels, the engine oil reaches the oil sump. The timing chain 9runs through the oil sump and transports the engine oil upwards
to the cylinder head. Through the bore bk the oil reaches the camshaft bl and the valves.

2-5E
8
7
1
2
3
4
4
5
6
9
10 11
Oil circuit 660 SMC (model 2003)
The oil pump 1pumps the engine oil past the by-pass valve 2through the oil filter 3. After the oil filter, an oil lead branches
off to a jet 4which sprays engine oil onto the piston pin bearing and piston head. The second oil lead takes the main flow of oil
to the second jet 4and the microfilter 5, which filters out even the finest impurities. The cleaned engine oil is pumped through
the oil lead and the clutch cover into the crankshaft to the connecting rod bearing 6and drips into the crankcase. An additional
oil pump 7sucks the engine oil out of the crankcase and pumps it through the oil line 8to the gear wheels of the 4th and 5th
gear. Via the gear wheels, the engine oil reaches the oil sump. The timing chain 9runs through the oil sump and transports the
engine oil upwards to the cylinder head. Through the bore bk the oil reaches the camshaft bl and the valves.