Suzuki RG250 User manual

•
~----------~ ~ ~ ' --
99SQ8-'286101E

FOREWORD
The SUZUKI RG250 has been developed as a new generation motorcycle. It is packed
with highly advanced design concepts including automatic exhaust control system, a liquid
cooling system, a G.D. ignition system, an positive damping fork and a full-floater suspen-
sion system. Combined with precise control and easy handling the RG250 provides excel-
lent performance and outstanding riding comfort.
This service manual
has been produced primarily for experienced mechanics whose job is
to inspect, adjust, repair and service SUZUKI motorcycles. Apprentice mechanics and
do-it-yourselfmechanics, will also find this manual an extremely useful guide.
Model RG250 manufactured to standard specifications is the main subject matter of
this manual. However, the RG250 machines distributed in your country might differ
in minor respects from the standard-specification and, if they do, it is because some minor
modifications (which are of no consequence in most cases as far as servicing is concerned)
had
to be made to comply with the statutory requirements of your country_
This manual contains up-to-date information at the time of its issue. Latermade modifi-
cations and changes will be explained to each SUZUKI distributor in respective markets,
to whom you
are kindly requested to make query about updated information, if any.
SUZUKI MOTOR CORPORATION
Motorcycle Technical Service Department
C: C OP YRIGHT SUZUKI MOTOR CORPORATION 1990

VIEW OF SUZUKI RG250 (FULL COWLING)
RIGHT SIDE
LEFT SIDE

GROUP INDEX
GENERAL INFORMATION
PERIODIC MAINTENANCE AND
TUNE-UP PROCEDURES
"------
IENGINE
r
LCOOLING SYSTEM
FUEL AND LUBRICATION SYSTEM
ELECTRICAL SYSTEM
CHASSIS
SERVICING INFORMATION
RG250H (,87 -MODEL)

VIEW OF SUZUKI RG250 (HALF COWLING)
RIGHT SIDE
LEFT SIDE

GENERAL INFORMATION
,--------------- CONTENTS -------
SERIAL NUMBER LOCATION ·· ·....··· .. · .. ··············· .. ···· ····· · ·· · .. 1- 1
FUEL, OIL AND COOLANT
RECOMMENDATION
···················· · ············ ··· ········ .... ........ ..·1- 1
BREAKING-IN PROCEDURE ········· ·· · ························· ········ ···· 1- 2
CYLINDER IDENTIFICATION············· ····························· ······· 1- 2
SPECIAL MATER IALS ········································· ················ 1- 3
PRECAUTION AND GENERAL INSTRUCTION .. ········.. ············ 1- 5
SPECIFICATIONS··············· ·························· ·· · ······ · ··········· ·1- 6

I-I GENERAL INF ORMATION
SERIAL NUMBER LOCATION
The frame se r ia l number or V.1. N. (Vehicle Identi-
fication Number) CD is sta mp ed on the steering
head pipe. T he engine serial number @ is locat ed
on the le ft sid e of the cran kcase. T hese numbers
are requir ed esp e ci ally f or registering the machi ne
and orde ri ng spare part s.
FUEL, OIL AND COOLANT
RECOMMENDATION
FUEL
Gasol ine u se d should be graded 85 -95 octane in
R
es earch Me thod and should be an unle ade d or
low-lead type where they are available.
EN GINE OIL
Use S UZUK I "CC I" o il or SU ZUKI eel Super
oil. Th ey are for mulated to gi ve best engine per·
formance with le ast combustion chamber depos it s,
least preignitio n, maximum spark plug lif e a nd
best lubrication. If they are not available, a good
quality T WO-S TRO KE 01 L (non- diluent typ e)
should be used.
TRANSMISSION OIL
Use a good qua lity S AE 20W/40 malt i- grade m otor
oi I.
BRAKE FLUID
Spe ci ficat ion and
class i ficat ion :
99000-23021
SAE J1 703.
DO T3 or DD T4
SUZU KI Brake fluid
I WARNING:
* Since the brake system of this motorcycle
is filled with a glycol-based brake fluid by
the manufacturer, do not use or mix differ -
ent types of fluid such as silicone-based
and petroleum-based
fluid for refilling the
system, otherwise serious damage
will
result.
* Do not use any brake fluid taken from old
or used or unsealed containers.
* Never re- use brake fluid left over from the
prevIous servicing and stored for a long
period.
FRONT FORK OIL
Us e th e f or k oil = 10.

COOLANT
Use an anti-freeze & Summer coolant compatible
with aluminum radiator, mixed with distilled water
only. at the ratio of 50 : 50.
WATER FOR MIXING
Use distilled water only _ Water other than distilled
wa ter can corrode and . dog the aluminum radiator.
ANT1-FREEZE & SUMMER COOLANT
The coolant performs as corrosion and rust inhibi-
tor as well as anti-freeze. Therefore, the coolant
should be used at all times even though the atmos-
pheric temperature in your area does not go down
to freezing point.
SUZUKI recommends the use of SUZUKI GOLD-
EN CRUISER 1 200 anti-freeze & summer coolant.
If this is not available, use an equivalent which is
compatible with aluminum radiator.
REQUIRED AMOUNT OF WATER/ COOLANT
Solution capacity (total): 1 500 ml
Water
30%
1050 ml
Coolant 450 ml
--Water
900ml
40%
Coolant 600
ml
~
-Water 750
ml
50 % -Coolant
750ml
I CAUTION:
Mixing of anti-freeze & summer coolant
should be limited
to 60 %. Mixing beyond it
would reduce its efficiency. If the anti-freeze
& summer coolant mixing ratio is below 30 %.
rust inhibiting performance is greatly reduced.
Be sure to mix it above 30% eve n tho . ugh the
atmospheric temperature does
not go down to
freezing point.
Every new
unit is filled with anti-leakage
material, Bar
's le ak.
GENERAL INFORMATION 1 -2
BREAKING-IN PROCEDURE
During manufacture only the best possible materi-
als are used and all machined parts are finished to a
ve ry high standard but it is still necessary to allow
the moving parts to "BR EAK -IN" before subject-
ing the engine
to maximum stresses. The future
performance and reliability
of the engine depends
on the
care and restraint exercised during its early
life. The general rul
es are as follows:
•
Keep to these breaking-in engine speed limits:
Initial 800 km Below 6 000
rlmin
Up to 1 600 km Below 8 000 rlmin
Over 1 600 km Below
12000 rlmin
• Upon reaching an odometer reading of 1600
km you can subject the motorcycle to full
throttle operation.
However, do not exceed
12000 rlmin at any
time.
• Do not maintain constant engine speed for an
extended time period during any portion of the
break-in.
Try to va ry the throttle position.
CYLINDER IDENTIFICATION
The two cylinders of this engine are identified as
left and right cylinder (as viewed by the rider on
the seat).

1-3 GENERAL I NFORMAl ION
SPE CIAL MATERIALS
The materials listed below are needed for maintenance work on the RG 250, and should be kept on ha nd
for ready use. They supplement such standard materials as cleaning fluids, lubricants, emery cloth and the
like. How
to use them and where to use them are described in the text of this manual.
Mater ia l Part P
age Part P
age
~:=J
• Oil
seals
3·21 • Wheel bearings 7·14
3-33
7·45
•
Throttle grip 7-46
• Sprocket
mounting drum bearing
' il " • Speedometer cable 7·
55
• Swing arm bearing and
dust seal
• Tachometer cable Brake pedal shaft
'Sl-."", .J
•
• Cushion lever bearing 7·56
SUZUKI • Steering stem bearings and races 7·33
• R
ear shock bearing 7·
56
SUPER GREASE "AU • Clutch lever
and release
99000-25010
• Side stand
• Clutch release 3
·2 7
~
. - ~~ .
SUZUKI MOLY PASTE
99000 -25140 • Mating surfaces
of upper 3·37 • Water temperature
gauge
4·10
~
and lower crankcase
- , .;' -• Mechanical
seal
4- 8 ~ .
SUZUKI BOND
No. 1207B
99000 - 31140
• Brake
fluid
2-14
SUZUKI BRAKE FLUID
99000 ·23021 (O.5L) • Oil
seal outer surface 3·
36
~
~ "'i
~
-
~
THREAD L OCK " ' 322 "
99000· 32110
~
• Gearshift shaft stopper 3·31
•
Kick starter gea r retainer 3·32
bolt
=-
•
. '--=:-
THREAD LOCK SUPER
"1303" 99000-32030

GENERAL INFORMATION 1-4
Mat e rial
Part
Page P.rt
p,,.
• Generator rotor nut
3·38
I'".
~~
~.
'-=-
THREAD LOCK "1324"
99000·32 1 20
• Gearshift cam guide screw 3-32
I'".
• Gearshift pawl lifter screw 3·32
~~
• Countershaft bearing-
3·39
I'\i1l
retainer
'--=-'
THREAD LOCK SUPER
"13338" 99000-32020
• To prevent leakage of
cooling solution from small
hole.
SUZUKI BAR's LEAK
99000·24240
• Cooling solution
SUZUK I GOLDEN
CRUI SER 1200 !2L)
99000·24120
• Disc
bolt
].15
I'".
7·46
}!:,q
.'
i§l§
'-=-
THREAD LOCK "1360"
99000-32130
• Stator securi ng screws. 3·38
I'".
6- 5
~~
•
Front fork damper rod bolt
7-27
I'Th1§
• Reed
valve
3·22
--
THREAD LOCK "1342"
99000-32050