Suzuki RM 250 2003 Application guide

OWNER’S SERVICE MANUAL

This manual should be considered a permanent part of
the motorcycle and should remain with the motorcycle
when resold or otherwise transferred to a new owner or
operator.
The manual contains important safety information and
instructions which should be read carefully before
operating the motorcycle.

GROUP INDEX
GENERAL INFORMATION 1
PERIODIC MAINTENANCE 2
ENGINE DISMOUNTING AND MOUNTING
3
CYLINDER, CYLINDER HEAD AND PISTON
4
CLUTCH 5
KICK STARTER 6
MAGNETO ROTOR AND STATOR 7
TRANSMISSION AND CRANKSHAFT
8
FUEL SYSTEM 9
COOLING SYSTEM 10
EXHAUST VALVE 11
CONSTRUCTIONS 12
FRONT AND REAR WHEELS 13
FRONT AND REAR BRAKES 14
FRONT FORK AND STEERING 15
REAR SUSPENSION 16
ELECTRICAL SYSTEM 17
TROUBLESHOOTING 18
SERVICE DATA 19
© COPYRIGHT SUZUKI MOTOR CORPORATION 2003
FOREWORD
This manual is presented as a means whereby you
can maintain your RM250 in top working condition
at all times. Your riding skill and the maintenance
steps outlined in this manual will assure you of top
performance from your machine under any type of
competition.
We sincerely wish you and your Suzuki motorcycle
a successful partnership for many years of happy
riding.
All information, illustrations, photographs and speci-
fications contained in the manual are based on the
latest product information available at the time of
publication. Due to improvements or other changes,
there may be some discrepancies in this manual.
Suzuki reserves the right to make production
changes at any time, without notice and without
incurring any obligation to make the same or similar
changes to vehicles previous built or sold.
Suzuki Motor Corporation believes in conservation
and protection of Earth’s natural resources. To that
end, we encourage every vehicle owner to recycle,
trade in, or properly dispose of, as appropriate,
used motor oil, engine coolant, and other fluids, and
tires.
WARNING/CAUTION/NOTE
Please read this manual and follow its instructions
carefully. To emphasize special information, the
symbol !and the words WARNING, CAUTION and
NOTE have special meanings. Pay special attention
to the messages highlighted by these signal words:
NOTE:
Indicates special information to make maintenance
easier or instructions clearer.
!WARNING
Indicates a potential hazard that could
result in death or injury.
CAUTION
Indicates a potential hazard that could
result in motorcycle damage.

HOW TO USE THIS MANUAL
TO LOCATE WHAT YOU ARE LOOKING
FOR:
1. The text of this manual is divided into sections.
2. The section titles are listed in the GROUP INDEX.
3. Holding the manual as shown at the right will allow you to find
the first page of the section easily.
4. The contents are listed on the first page of each section to
help find the item and page you need.
COMPONENT PARTS AND WORK TO BE DONE
Under the name of each system or unit, is its exploded view. Work instructions and other service information
such as the tightening torque, lubricating points and locking agent points, are provided.
Example: Front wheel
35 N.m
(3.5 kgf-m, 25.5 lb-ft)
10 N.m
(1.0 kgf-m, 7.0 lb-ft)
FWD

SYMBOL
Listed in the table below are the symbols indicating instructions and other information. The meaning of each
symbol is also included in the table.
SYMBOL DEFINITION SYMBOL DEFINITION
Torque control required.
Data beside it indicates specified
torque.
Apply THREAD LOCK SUPER “1303”.
99000-32030
Apply oil. Use engine oil or transmission
oil unless otherwise specified. Use SUZUKI FORK OIL SS-05 or equivalent fork oil.
99000-99001-SS5
Apply SUZUKI SUPER GREASE “A”.
99000-25030 (USA)
99000-25010 (Others)
Use SUZUKI REAR SUSPENSION OIL
SS-25 or equivalent rear suspension oil.
99000-99001-S25
Apply SUZUKI SILICONE GREASE.
99000-25100 Use engine coolant.
Apply SUZUKI BOND “1207B”.
99000-31140 Apply or use brake fluid. (DOT-4)
Apply THREAD LOCK SUPER “1322”.
99000-32110 Use special tool.
Apply THREAD LOCK SUPER “1360”.
99000-32130 Indication of service data.
Apply THREAD LOCK SUPER “1342”.
99000-32050 Replace a part with a new one when reassembling.

1
GENERAL INFORMATION 1-1
CONTENTS
GENERAL INFORMATION
WARNING/CAUTION/NOTE ....................................................................... 1- 2
WARNING/CAUTIONS FOR SERVICING ................................................... 1- 2
GENERAL CONSIDERATIONS .................................................................. 1- 5
SERIAL NUMBER LOCATION .................................................................... 1- 6
LOCATION OF PARTS ............................................................................... 1- 7
FUEL AND OIL RECOMMENDATION ........................................................ 1- 8
OPERATING INSTRUCTIONS .................................................................... 1- 9
STARTING THE ENGINE ...................................................................... 1- 9
STOPPING THE ENGINE ..................................................................... 1-10
TRANSMISSION ................................................................................... 1-10
BREAK-IN (RUNNING-IN) ........................................................................... 1-10
WHEN THE MOTORCYCLE IS NEW ................................................... 1-10
WHEN ENGINE PARTS ARE REPLACED ........................................... 1-10
COUNTRY AND AREA CODES .................................................................. 1-11

1-2 GENERAL INFORMATION
WARNING/CAUTION/NOTE
Please read this manual and follow its instructions carefully. To emphasize special information, the symbol
and the words WARNING, CAUTION and NOTE have special meanings. Pay special attention to the mes-
sages highlighted by these signal words.
NOTE:
Indicates special information to make maintenance easier or instructions clearer.
WARNING/CAUTIONS FOR SERVICING
!WARNING
Indicates a potential hazard that could result in death or injury.
CAUTION
Indicates a potential hazard that could result in motorcycle damage.
!WARNING
Never run the engine indoors or in a
garage. Exhaust gas contains carbon mon-
oxide, a gas that is colorless and odorless
and can cause death or severe injury.
Only run the engine outdoors where there
is fresh air.
!WARNING
Hot engine and muffler can burn you.
Wait until the engine and muffler cools
before servicing.

GENERAL INFORMATION 1-3
!WARNING
Fuel can catch on fire if you do not handle
it properly. Gasoline vapors can catch fire
easily.
Do not smoke when servicing the machine.
Do not service the machine in an area
where there are open flames or sparks.
!WARNING
Brake fluids and engine coolant can be
hazardous to humans and pets. Brake fluid
and engine coolant are harmful or fatal if
swallowed, and harmful if it comes in con-
tact with your skin or eyes.
Keep brake fluid and engine coolant away
from children. Call your doctor immedi-
ately if swallowed, and induce vomiting.
Flush eyes or skin with water if either
brake fluid or engine coolant gets in eyes
or comes in contact with skin.
!WARNING
Servicing the machine with engine running
can be hazardous. You can be caught in
the moving parts such as the drive chain,
sprockets etc.
Be sure to stop the engine when servicing
the machine.
!WARNING
Servicing the machine without proper
clothes and protective gear can be hazard-
ous. You can be injured if you do not wear
proper clothes and protective gear.
Be sure to wear proper clothes and shoes
for servicing and wear protective glasses,
mask or gloves as necessary.

1-4 GENERAL INFORMATION
!WARNING
* Proper service and repair procedures are important for the safety of the service mechanic and
the safety and reliability of the motorcycle.
* When 2 or more persons work together, pay attention to the safety of each other.
* When handling toxic or flammable materials, make sure that the area you work in is well-venti-
lated and that you follow all of the material manufacturer’s instructions.
* Never use gasoline as a cleaning solvent.
* After servicing the fuel, oil, exhaust or brake systems, check all lines and fittings related to the
system for leaks
CAUTION
* If parts replacement is necessary, replace the parts with Suzuki Genuine Parts or their equiva-
lent.
* When removing parts that are to be reused, keep them arranged in an orderly manner so that
they may be reinstalled in the proper order and orientation.
* Be sure to use the special tools when instructed.
* Make sure that all parts used in reassembly are clean. Lubricate them when specified.
* Use the specified lubricant, bond, or sealant.
* Whenever you remove oil seals, gaskets, packing, O-rings, locking washers, self-locking nuts,
circlips and certain other parts as specified, be sure to replace them with new ones. Also,
before installing these new parts, be sure to remove any left over material from the mating
surfaces.
* Never reuse a circlip. When installing a new circlip, take care not to expand the end gap larger
than required to slip the circlip over the shaft. After installing a circlip, always ensure that it is
completely seated in its groove and securely fitted.
* Use a torque wrench to tighten bolts/nuts to the specified torque. Wipe off grease and oil if a
thread is smeared with them.
* After reassembling, check parts for tightness and proper operation.
* Use special tools where specified.
* To protect the environment, do not unlawfully dispose of used motor oil and other fluids.
* To protect Earth’s natural resources, properly dispose of used motorcycle and parts.

GENERAL INFORMATION 1-5
GENERAL CONSIDERATIONS
• Wear a helmet and goggles
A helmet is the most important piece of gear to
wear. Helmets do not reduce essential vision or
hearing. Generally, helmets do not cause or
intensify injury if you crash. Helmets simply help
your skull protect your intelligence, your memory,
your personality, and your life.
Your eyesight is equally valuable. Wearing suit-
able eye protection can help keep your vision
unblurred by the wind and help shield your eyes
from branches and airborne matter like bugs, dirt,
or pebbles kicked up by tires. Wear a helmet and
eye protection every time you ride.
• Wear protective gear
Wear proper clothing when you ride. Avoid loose
clothes or scarves, which could get caught in
moving parts. Abrasion injuries can be minimized
by wearing protective clothing including gloves,
strong boots that fit over the ankle, long pants,
and a long sleeve shirt or jackets. Experienced
riders often wear a kidney belt and chest or back
protector for additional comfort and protection.
• Inspect your machine before riding
Before each use, perform an inspection per
“PERIODIC MAINTENANCE” section starting on
page 2-2.
• No Passengers
Suzuki RMs are designed for the rider only.
• Practice on level ground
Before you begin riding, you should find a good
place to practice the skills you need to ride
safely. Find a flat, open area with enough space
to maneuver. Check with your Suzuki dealer or
call police department if you do not know where
you can ride.
Review the controls on your motorcycle before
riding.
• Know your limits
Always ride within the boundaries of your own
skills. Knowing these limits and staying within
them will help you avoid accidents. Ride only in
events appropriate for your experience.
Safely competing on a motorcycle requires that
your mental and physical skills are fully part of
the experience. You should not attempt to oper-
ate a motor vehicle, especially one with two
wheels, if you are tired or under the influence of
alcohol or other drugs. Alcohol, illegal drugs, and
even some prescription and over-the-counter
drugs and cause drowsiness, loss of coordina-
tion, loss of balance, and loss of good judge-
ment. If you are tired or under the influence of
alcohol or other drugs, PLEASE DO NOT RIDE
your motorcycle.
• Conclusion
The actions of other riders are unpredictable.
Your motorcycle’s condition can change. These
factors can best be dealt with by giving every ride
your full attention.
Circumstances beyond your control could lead to
an accident. You need to prepare for the unex-
pected by wearing a helmet and other protective
gear, and practicing safe riding techniques to
minimize the damage to you and your machine.
May all of your rides on your new Suzuki be winning
rides!

1-6 GENERAL INFORMATION
SERIAL NUMBER LOCATION
The frame number
1is stamped on the steering head as shown in the photograph. The engine serial num-
ber
2is stamped on the right side of the crankcase assembly.
Write down the serial numbers here for your future reference.
Frame No.
Engine No.

GENERAL INFORMATION 1-7
LOCATION OF PARTS
1Clutch lever
2Engine stop switch
3Clutch cable adjuster
4Throttle grip
5Front brake lever
6Fuel tank cap
7Starter knob
8Gearshift lever
9Fuel valve
0Kick starter lever
ARear brake pedal

1-8 GENERAL INFORMATION
FUEL AND OIL RECOMMENDATION
This motorcycle is of the two-stroke design, which requires a
premixture of gasoline and oil.
Gasoline: Use only unleaded gasoline of at least 90
pump octane (R/2 + M/2). .... For Canada
Use only unleaded gasoline of at least 95
octane (Research Method). .... For other
countries
Engine oil: MOTUL 800 2T FACTORY LINE OFF
ROAD or an equivalent Two Cycle Racing
Lubricant.
Mixing ratio: 30 : 1
Fuel tank capacity: 8.0 L (2.1/1.8 US/lmp gal)
NOTE:
* Mix gasoline and the engine oil thoroughly when the tempera-
ture is below 0 °C (32 °F). Vegetable-based oils can separate
easier than mineral oils.
* Use premixture oil as soon as possible after mixing, or lubrica-
tion performance of the engine oil can decrease.
* Do not mix vegetable-based oil and mineral oil.
CAUTION
A mixture containing too little oil will cause piston sei-
zure. Too much oil will cause excessive carbon forma-
tion resulting in preignition, fouled spark plug and
loss of engine power.
Mix fuel and the engine oil at the ratio of 30:1.
Gasoline
(L) Oil (ml) Gasoline (US gal.) Oil (US oz) Gasoline (Imp gal.) Oil (Imp oz)
5.0 167 1 4.3 1 5.4
10.0 333 2 8.6 2 10.7
15.0 500 3 12.8 3 16.0
20.0 667 4 17.1 4 21.4

GENERAL INFORMATION 1-9
OPERATING INSTRUCTIONS
STARTING THE ENGINE
Inspect the transmission oil level, coolant level and air cleaner
condition before starting the engine.
When the engine is cold:
1) Turn the fuel valve lever to the “ON” position.
2) Shift the transmission into neutral.
3) Pull the bypass (starter) knob
1.
4) Close the throttle grip completely and depress the kick
starter lever forcefully.
5) Return the bypass (starter) knob when the engine revs at
steady speed.
When the engine is warm:
1) Turn the fuel valve lever to the “ON” position.
2) Shift the transmission into neutral.
3) Open the throttle 1/8 – 1/4 turn
Aand depress the kick
starter lever forcefully.
To restart after the motorcycle has fallen:
1) Shift the transmission into neutral.
2) Open the throttle completely and depress the kick starter
lever forcefully.
3) Close the throttle gradually as engine speed increases.
4) Wait until engine revs smoothly.
CAUTION
Racing the engine in neutral will exceed the engine
speed limit. Exceeding the engine speed limit can
damage the engine moving parts.
Do not race the engine at high speed to avoid the
engine damage.

1-10 GENERAL INFORMATION
STOPPING THE ENGINE
1) Shift the transmission into neutral.
2) Turn the fuel valve lever to the “OFF” position.
3) Push the engine stop switch
2to stop the engine.
TRANSMISSION
This motorcycle has a 5-speed transmission. Neutral is located
between low and 2nd. Engage first gear by pressing the lever
down from the neutral position. You can shift into higher gears
by lifting on the shift lever once for each gear. When neutral is
desired, press or lift the lever to the position halfway between
low and 2nd gear.
BREAK-IN (RUNNING-IN)
WHEN THE MOTORCYCLE IS NEW
1) Warm up the engine before starting off.
2) Ride for 1 hour using less than 1/2 throttle opening with vari-
ous throttle opening.
3) Ride for 1 hour using less than 3/4 throttle opening with vari-
ous throttle opening.
NOTE:
* The break-in (running-in) period is the period of greatest wear.
* The bolts and nuts of the new machine can loosen quickly. Be
sure to retighten the bolts and nuts during the break-in (run-
ning-in) period.
WHEN ENGINE PARTS ARE REPLACED
Follow the same procedure when any of the following parts are
replaced:
Piston
Piston ring
Cylinder
Crankshaft
Crankshaft bearing
!WARNING
Leaving the fuel valve in the “ON” position may cause
carburetor overflow. This can cause a fire or severe
engine damage when you start the engine.
Always leave the fuel valve in the “OFF” position
when the engine is not running.
N

GENERAL INFORMATION 1-11
COUNTRY AND AREA CODES
The following codes stand for the applicable country(-ies) and area(-s).
CODE COUNTRY or AREA
000
E-03
E-28
Japan
U. S. A.
Canada

2
PERIODIC MAINTENANCE 2-1
CONTENTS
PERIODIC MAINTENANCE
PERIODIC MAINTENANCE ........................................................................ 2- 3
PERIODIC MAINTENANCE CHART .................................................... 2- 3
INSPECTION BEFORE PRACTICE ...................................................... 2- 5
INSPECTION BEFORE RACE .............................................................. 2- 5
SPARK PLUG .............................................................................................. 2- 6
AIR CLEANER ............................................................................................. 2- 7
AIR CLEANER ELEMENT REMOVAL ................................................. 2- 7
WASHING .............................................................................................. 2- 7
INSTALLATION ..................................................................................... 2- 7
TRANSMISSION OIL ................................................................................... 2- 9
TRANSMISSION OIL LEVEL INSPECTION AND REPLENISHMENT ...... 2- 9
TRANSMISSION OIL CHANGE ............................................................ 2-10
ENGINE COOLANT ..................................................................................... 2-11
ENGINE COOLANT LEVELCHECK .................................................... 2-11
ENGINE COOLANT REPLENISHMENT ............................................... 2-12
ENGINE COOLING SYSTEM INSPECTION ......................................... 2-12
CLUTCH ....................................................................................................... 2-13
MAJOR ADJUSTMENT ........................................................................ 2-13
MINOR ADJUSTMENT ......................................................................... 2-13
THROTTLE CABLE ..................................................................................... 2-13
FUEL HOSE ................................................................................................. 2-14
FUEL VALVE ............................................................................................... 2-14
CYLINDER HEAD, CYLINDER AND PISTON ............................................ 2-15
CYLINDER HEAD ................................................................................. 2-15
CYLINDER ............................................................................................. 2-15
PISTON .................................................................................................. 2-15
EXHAUST VALVE ....................................................................................... 2-15
EXHAUST SILENCER ................................................................................. 2-16
DRIVE CHAIN AND SPROCKETS .............................................................. 2-16
DRIVE CHAIN SLACK .......................................................................... 2-16
DRIVE CHAIN ADJUSTMENT .............................................................. 2-16
20TH PITCH LENGTH ........................................................................... 2-17
DRIVE CHAIN LUBRICATION .............................................................. 2-17
SPROCKET INSPECTION .................................................................... 2-17

2-2 PERIODIC MAINTENANCE
CONTENTS
PERIODIC MAINTENANCE
DRIVE CHAIN GUIDE, BUFFER, CONTROL ROLLER ............................. 2-18
DRIVE CHAIN GUIDE ........................................................................... 2-18
DRIVE CHAIN GUIDE BUFFER ........................................................... 2-18
DRIVE CHAIN CONTROL ROLLER .................................................... 2-18
BRAKES ...................................................................................................... 2-18
BRAKE FLUID LEVEL ......................................................................... 2-18
BRAKE PAD ......................................................................................... 2-19
FRONT BRAKE LEVER ADJUSTMENT .............................................. 2-19
BRAKE PEDAL HEIGHT ADJUSTMENT ............................................ 2-20
FRONT FORK ............................................................................................. 2-20
AIR PRESSURE ADJUSTMENT .......................................................... 2-20
STEERING .................................................................................................. 2-20
REAR SUSPENSION .................................................................................. 2-21
WHEELS AND TIRES ................................................................................. 2-21
TIRE PRESSURE ................................................................................. 2-21
WHEEL RIM .......................................................................................... 2-21
SPOKE NIPPLE .................................................................................... 2-21
LUBRICATION ............................................................................................ 2-23

PERIODIC MAINTENANCE 2-3
PERIODIC MAINTENANCE
PERIODIC MAINTENANCE CHART
It is very important to inspect and maintain the machine regularly. Follow the guideline in the chart. The life
of parts varies depending on the riding conditions. Perform more often than shown in the chart if you use the
motorcycle under severe conditions.
Interval races Every
race Every 3 races Every 5 races Remarks
Service
Item hours Every 2 hours Every 6 hours Every 10 hours
Spark plug I R —
Air cleaner C — — Replace air cleaner element as necessary.
Transmission oil — R — Change after 1st initial break-in.
Cooling-system I — — Replace radiator hose and engine coolant every year.
Flushing for overhaul or storage.
Clutch I — — Replace clutch plates as necessary.
Throttle and clutch cable I & L — —
Carburetor I — —
Fuel hose I — — Replace every 4 years.
Piston — — R
Piston ring — R —
Cylinder head, cylinder — C —
Exhaust valve — C —
Crankshaft and
transmission bearing
Inspect asrequired
Exhaust silencer I — —
Drive chain I & L R — Adjust slack every 30 minutes.
Engine sprocket I — —
Rear sprocket I — — Check and retighten sprocket bolts at initial and subsequent 10 minutes of riding and
each race thereafter.
Drive chain buffer — R —
Drive chain guide — R —
Kick starter lever I & L — —
Brake I — — Replace brake hose and fluid every year.
Front fork oil — R — Change after 1st initial break-in.
Front fork I — — Check front fork inner tube frequently for
abnormality. Check the air pressure.
Rear suspension
system pivoting portion I——
Check rear suspension system frequently
and apply the grease to the pivoting portion
as necessary.

2-4 PERIODIC MAINTENANCE
NOTE: R = Replace, C = Clean, T = Tighten, I = Inspect and clean, adjust lubricate or replace if necessary,
L = Lubricate.
Interval races Every
race Every 3 races Every 5 races Remarks
Service
Item hours Every 2 hours Every 6 hours Every 10 hours
Tire I — —
Spoke nipple I — — Inspect every 20 min. up to initial 2 hours
then check before each ride.
Steering I — —
Bolts and nuts T — — Retighten every 1 hour.