KTM 85 SX 2004 Operating instructions

85 SX
REPARATURANLEITUNG
MANUALE DI RIPARAZIONE
MANUEL DE RÉPARATION
MANUAL DE REPARACIÓN
ART.NR.: 3.206.008-E
REPAIRMANUAL2004

REPAIRMANUAL2004 85 SX
KTM Group Partner

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

Repair manual KTM 85 SX Art No 3.206.008-E
IMPORTANT INFORMATION
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.
T
he respective headings can be entered in the list of contents.

Repair manual KTM 85 SX Art No 3.206.008-E
EXPLANATION - UPDATING
Edition 06/2003
This repair manual contains the following supplements:
3.206.008-E Repair Manual 85 SX
Basicversion Modelyear 2004
06/2003

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.
KTM Austria’s certificate of achievement for its quality system ISO 9001 is the beginning of an
ongoing total reengineered quality plan for a brighter tomorrow.
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.: 3.206.008-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

GENERAL INFORMATION
Repair manual KTM 85 SX Art No 3.206.008-E
CARBURETOR ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
BLEEDING OF THE HYDRAULIC CLUTCH . . . . . . . . . . . . . . . . . . . . . . . . . .2-3
SPECIAL TOOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4
CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
STORAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
INDEX
2-1
2

2-2
Repair manual KTM 85 SX Art No 3.206.008-E
B
C
D
A
Carburetor adjustment
Basic information on the original carburetor setting
The original carburetor setting was adapted for an altitude of approx. 500 meters (1600 ft.) above sea level, and the ambient
temperature of approx. 20° C (68° F), mainly for off-road use and central European premium-grade fuel (ROZ 95).
Mixing ratio 2-stroke motor oil : super fuel 1:40
Basic information of changing the carburetor setting
Always start out from the original carburetor setting. Essential requirements are a clean air filter system, air-tight exhaust system
and an intact carburetor. Experience has shown that adjusting the main jet, the idling jet and the jet needle is sufficient and that
changes to other parts of the carburetor will not greatly affect engine performance.
RULE OF THUMB: high altitude or high temperatures ➞choose leaner carburetor adjustment
low altitude or low temperatures ➞choose richer carburetor adjustment
 WARNING 
–ONLY USE PREMIUM-GRADE GASOLINE ROZ 95 MIXED WITH HIGH-GRADE TWO-STROKE ENGINE OIL. OTHER TYPES OF GASOLINE CAN CAUSE ENGINE
FAILURE, AND THEIR USE WILL VOID YOUR WARRANTY.
–O
NLY USE HIGH-GRADE 2-STROKE ENGINE OIL OF KNOWN BRANDS (E. G.MOTOREX CROSS POWER 2T).
–N
OT ENOUGH OIL OR LOW-GRADE OIL CAN CAUSE EROSION OF THE PISTON. IFYOU USE TOO MUCH OIL, THE ENGINE CAN START SMOKING AND
FOUL THE SPARK PLUG.
–I
NTHE CASE OF A LEANER ADJUSTMENT OF THE CARBURETOR PROCEED CAUTIOUSLY. ALWAYS REDUCE THE JET SIZE IN STEPS OF ONE NUMBER TO
AVOID OVERHEATING AND PISTON SEIZURE.
NOTE: If the engine does not run properly, despite a changed adjustment look for mechanical faults and check the ignition system.
Basic information on carburetor wear
As a result of engine vibrations, the throttle valve, jet needle, and needle jet are subjected to increased wear. This wear may cause
carburetor malfunction (e.g. overly rich mixture). Therefore, these parts should be replaced after 1000 hours of using.
Idling range – A, Adjusting the idle speed
Operation with closed throttle valve. This range is influenced by the
position of the air control screw 1and the idle adjusting screw 2. Only
make adjustments when the engine is hot.
To this end, slightly increase the idling speed of the engine by means of
the idle adjusting screw. Turning it clockwise produces a higher idling
speed and turning the screw counterclockwise produces a lower idling
speed. Create a round and stable engine speed using the air control
screw (basic position of the air control screw = open by 1.5 turns). Then
adjust to the normal idling speed by means of the idle adjusting screw.
Opening up – B
Engine behavior when the throttle opens. The idle jet and the shape of
the throttle valve influences this range. If, despite good idling-speed and
part-throttle setting, the engine sputters and smokes when the throttle is
fully opened and develops its full power not smoothly but suddenly at
high engine speeds, the mixture to the carburetor will be too rich, the
fuel level too high or the float needle is leaking.
Part-throttle range – C
Operation with partly open throttle valve. This range is only influenced
by the jet needle (shape and position). The optimum part-throttle setting
is controlled by the idling setting in the lower range and by the main jet
in the upper range. If the engine runs on a four-stroke cycle or with
reduced power when it is accelerated with the throttle partly open, the
jet needle must be lowered by one notch. If the engine pings, especially
when accelerating under full power at maximum engine revs, the jet
needle should be raised.
If these faults should occur at the lower end of the part throttle range at
a four-stroke running, make the idling range leaner; if the engine pings,
adjust the idling range richer.
Full throttle range – D
Operation with the throttle fully open (flat out). This range is influenced
by the main jet and the jet needle. If the porcelain of the new spark plug
is found to have a very bright or white coating or if the engine rings,
after a short distance of riding flat out, a larger main jet is required. If
the porcelain is dark brown or black with soot the main jet must be
replaced by a smaller one.
main jet
jet needle
jet needle
idling jet
idling jet
throttle valve
1
2

2-3
Bleeding of the hydraulic clutch
–Take off cover together with rubber bellows.
–At the slave cylinder of the clutch, remove the bleeder nipple 1. It its
place, mount the bleeder syringe 2which is filled with SAE 10 (e.g.
Motorex Clutchfluid 75) hydraulic oil.
–Refill oil, until oil is discharged from the bore 3of the master cylinder
in a bubble-free state. Make sure that the oil does not overflow.
!
CAUTION
!
–H
AVING COMPLETED THE BLEEDING PROCEDURE, YOU HAVE TO VERIFY THAT THE
OIL LEVEL IN THE MASTER CYLINDER IS CORRECT.
–KTM USES BIODEGRADABLE HYDRAULIC OIL FOR THE HYDRAULIC CLUTCH
CONTROL. NEVER MIX BIODEGRADABLE HYDRAULIC OILS WITH MINERAL OILS.
–A
LWAYS USE BIODEGRADABLE HYDRAULIC OIL SAE 10 (E.G. MOTOREX
CLUTCHFLUID 75) TO FILL UP THE MASTER CYLINDER. NEVER REFILL WITH
MINERAL HYDRAULIC OIL OR BRAKE FLUID.
3
2
1

2-4
Repair manual KTM 85 SX Art No 3.206.008-E
SPECIAL TOOLS – ENGINE 85 SX
140
27
17
5
60
HOLZGABEL
SELBSTGEFERTIGT
WOODEN FORK PLATE
HOME MADE
FIG. DESCRIPTION PART NUMBER
1560.12.001.000 Universal engine work stand
2470.29.027.000 Clutch rivetting tool
36899 785 Loctite 243 blu 6 cm3
4510.12.011.000 Circlip plier
5503.29.050.000 Vent syringe for hydraulic clutch
6546.29.009.044 Magneto extractor M 27x1
7510.12.016.000 Protection cap
8151.12.018.200 Internal bearing puller 5-7 mm
9546.29.012.100 Holding spanner for flywheel
10 151.12.017.000 Bearing puller
11 470.29.006.000 Adjusting plate
12 584.29.037.031 Mounting tool inner ring NJ207
13 470.29.003.000 Clutch/Primary gear holder
3
2
1
5
7
12
6
4
9
10
8
13
11

2-5
Clean your motorcycle regularly in order to keep its painted finish looking shiny and new.
The best manner would be to use warm water that has been mixed with a commercially available washing detergent and a sponge.
The hard dirt can be removed before with the help of a soft water jet.
! CAUTION !
NEVER CLEAN YOUR MOTORCYCLE WITH A HIGH-PRESSURED CLEANER OR A HIGH-PRESSURED WATER JET. OTHERWISE THE WATER MIGHT RUN INTO THE
ELECTRICAL COMPONENTS, CONNECTORS, SHEATHED CABLES, BEARINGS, CARBURETOR ETC. AND CAUSE MAILFUNCTIONS, I.E., LEAD TO THE PREMATURE
DESTRUCTION OF THESE PARTS.
–You should use commercially available detergents to clean the motorcycle. Heavily soiled parts should also be cleaned with the
help of a paint brush.
–Before cleaning with water, plug the exhaust pipe to prevent water ingress.
–After the motorcycle has been rinsed with a soft water jet, it should be dried by air pressure and a cloth. Then take a short drive
until the engine has reached its operating temperature, and also operate the brakes. The heat also causes the water at the
inaccessible parts of the engine and the brakes to evaporate.
–Slide back the protective covers on the handlebar-mounted instruments so that any water that may have seeped into this part of
the motorcycle is allowed to evaporate.
–After the motorcycle has cooled down, oil and grease all the gliding bearing parts. Also treat the chain with a chain spray.
–To prevent failures in the electric system, you should treat the short circuit button with a contact spray.
If you want to put your motorcycle away for longer periods of time, please observe the following instructions:
–Clean motorcycle thoroughly (see chapter: CLEANING)
–Change engine oil (old engine oil contains aggressive contaminations).
–Check antifreeze and amount of cooling liquid.
–Let the engine warm up again, close fuel tap and wait until the engine dies off by itself. In this way, the carburetor jets are
prevented from becoming resin-clogged by the old fuel.
–Remove spark plug and fill in approx. 5 ccm of engine oil into the cylinder through the opening. Actuate kickstarter 10 times in
order to distribute the oil onto the cylinder walls and mount the spark plug.
–Let fuel flow out of tank into an appropriate basin.
–Correct tire pressure.
–Lubricate bearing points of the control levers, footrests, etc. as well as the chain.
–The storage place should be dry and not be subjected to overly great temperature fluctuations.
–Cover the motorcycle with an air permeable tarpaulin or blanket. Do not use airtight materials, as possible humidity might not be
able to escape and thereby cause corrosion.
 WARNING 
ITWOULD BE VERY BAD TO LET THE ENGINE RUN FOR A SHORT TIME DURING THE STORAGE PERIOD. THE ENGINE WOULD NOT GET WARMED UP ENOUGH
AND THE THUS DEVELOPED STEAM WOULD CONDENSE DURING THE COMBUSTION PROCESS AND CAUSE THE EXHAUST TO RUST.
USE AFTER PERIOD OF STORAGE
–Fill up tank with fresh fuel.
–Check motorcycle as before each start (see driving instructions).
–Take a short, careful test ride first.
NOTE: Before you put your motorcycle away for the winter, you should check all parts for their function and wear. Should any
service jobs, repairs, or any refitting be necessary, you should have them carried out during the off-season (lower workload at
mechanics' shops). This way, you can avoid the long waiting times at your shop at the beginning of the next biking season.
CLEANING
STORAGE