Tecnico cb250 User manual

Introduction
This service manual describes the service procedures fór
the CB250.
This Model Specific Manual includes every service proce-
dure that is of a specific natura to this particular model.
Basic service procedures that are common to other Honda
Motorcycle/Motor Scooter/ATVs are coveredin the Corn-
mon Service Manual.
This Model Specific Service Manual should be used
together with the Common Service Manual in order to
provide complete service information on all aspects of
this motorcycle,
Throughout the manual, the following abbreviations are
used to
identify individual rnodels.
CODE
AREA (TYPE)
E
U.K.
U
Australia
Performing the first scheduled maintenance is very im-
portant. It compensates for the initial wear that occurs
duríng the break-in periodo .
Sections 1 and 3 applv whole motorcycle. Sectíon 2 íl-
lustrates procedures for removal/installation of cornpo-
nents that may be required to perform service described
in the followinq sections.
Sections 4 through 17 describe parts of the motorcycle,
grouped according to location.
Find the section you want on this page, then turn to the
table of contents on the first page of the section,
\I1ost sections describe the service prccedure throuqh
svstern illustration. Refer to the next page for details on
",OW to use thís manual.
f you dont know the source of the trouble, go to sec-
ion 18 Troubleshooting.
ALL INFORMATION, ILLUSTRATIONS, DIREC-
TIONS AND SPECIFICATIONS INCLUDED IN THIS
PUBLlCATION ARE BASED ON THE LATEST
PRODUCT INFORMATION AVAILABLE AT THE
TIME OF APPROVAL FOR PRINTING. HONDA
MOTOR CO., LTD. RESERVES THE RIGHT TO
MAKE CHANGES AT ANY TIME WITHOUT NO-
TICE
AND WITHOUT INCURRING ANY OBLlGA-
TION WHATEVER. NO PART DF THIS PUBLlCA-
TION MA y BEREPRODUCED WITHOUT WRITTEN
PERMISSION. THIS
MANUAL IS WRITTEN FOR
PERSONS WHO" HAVE ACQUIRED BASIC
KNOWLEDGE OF MAINTENANCE ON HONDA
MOTORCYCLES,
HONDA MOTOR CO., LTD.
SERVICE PUBLlCATION OFFICE
rte of Issue: March, 1992
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Contents
General Information
Frame/B6dy panels/Exhaust System
Maintenance
Lubrication System
Fuel System
Engine Removal/lnstallation
Cylinder Head/Cylinder/Piston
Clutch/Gearshift Linkage
Crankshaft/T ransm ission
Front Wheel/Suspension/Steering
Rear Wheel/Suspension
Brake System
Charging Systeml Alternator
Ignition System
Electric Starter IStarter Clutch
Lights/Meters/Switches
Wiring Diaqrarn
Troubleshooting

How To Use This Manual
Finding The Information You Need
This manual is devided into sections which cover each of the
major components of the motorcycle.
To quickly find the section you are interested in, the first page
of each
sections is marked with a black tab that lines up with
one of the thumb index tabs before this page.
The first page of each section lists the table of contents with-
in the section.
Read the service information and troubleshooting related to
the section before you begin working.
• An index of the entire book is provided in the last chapter
to directly locate the information you need.
Understanding The Instructions
• The removal and installation of parts are for the rnost part illustrated by large and clear illustr ations that should provide
the reader with visual aid in understanding the major point for servicing.
The system illustrations are augmented by call outs whose numbers or letters indicate the order in which the parts should
be removed or installed.
The sequence of steps represented numerically are diffferentiated from the ones represented alphabetically to notify
the reader that they must perform these steps separately.
For ex-ample, if the steps prior and up to camshaft rernoval are performed with the engine installed, but the subsequent
steps like cylinder head removal require engine removal, the callouts are grouped in numerical and alphabetical orders.
The illustrations may contain symbols to indicate necessary service procedures and precautions that need to be taken.
Refer to the next page for the meaning of each symbol.
• Also in the illustration is a chart that lists informatión such as the order in which the parts is removal/installed, the name
of
the part. and some extra notes that may needed.
Step by step instructions are provided to supplement the illustrations when datailed explanation of the procedure is
necessary or illustrations alone would not suffice.
Standard workshop procedures and knowledge covered in the Common Service Manual are abbreviated in this manual.
11-8
r
Detailed description
of the procedure
----
--- .,..,- .. --
~-- .......... _--
-_.- ... _------.
"----------
-----
------_-.
-_-..._-----_.
-.-._----_--.
---------.
----------
---------
I~-
1--- -1
I ~:::.::.::=: - - - -]
Symbols
_ .... _-----
.e-...o_-.. _
.:.:: -::'-:'::"-::'::::-':::'-1
11-7
System illustration
Step
sequence
(numerals
or alphabets)
Part name
Number of parts
Extra notes or precautions
related to the service procedure

CB250 Addendum
Specifications
General
Item Specifications
Dimensions
Frame
Engine
Overall length
Overall width
Overall height
Wheel base
Seat height
Footpeg height
Ground clearance
Dry weight
Curb weight
Maximum weight capacíty
Frame type
Front suspensión
Front wheel travel
Rear suspension
Rear wheel travel
Hear damper
Front tiresize
Rear tire size
Tire brand (Bridgestone)
Tirebrand (Dunlop)
Tire brand (Yokohama)
Tire brand (IRC)
Tire brand (Pirelli)
Front brake
Hear brake
Caster
angle
Traillength
Fuel tank capacity
Fuel tank reserve capacity
Bore and stroke
Displacement
Compression ratio
Valve train
Intake valve opens' (att mm lift)
Intake valve closes (at 1 mm lift)
Exhaust valve opens (at 1 mm lift)
Exhaust valve closes (at 1 mm lift)
Lubrication system
Oil pump type
ICo
olinp system
.•- Ai r fi/tration
Crankshaft type
Engine weight
Firing order "
Cylinder arranqernent
Cylinder number i'I.
ti FRONT
FR/RR
FR/RR
FR/RR
FR/RR
FR/RR
2,090
mm"{82;3 in)
755
mm (29.7 in)
1,090
mm (42.9"in)
1,425
mm (56.1 in)
755
mm (29.7 in)
306
mm (12.0 in)
165
mm (6.5 in)
132
kg(291 lbs)
146 kg
(322 lbs)
160 kg(352Ibs)
Diamond
Telescopic fork
123 mm (4.8 in)
Swingarm
110 mm (4.3 in)
Conventiorial type oildamper
90/100 - 18 545
120/90 - 16635
K300MNK327 AG
MT65/MT65"
Hydraulicsingle disc
Mechanical leading/trailingshoe
28°30'
109 mm (4.3 in)
16 e(4.2 U5 gal, 3.5 Imp gal)
3e (0.8 U5gal, 0.7 Imp gal)
53 x 53 mm (2.1 x 2.1 in)
234 cm" (14.3
cu-in)
9.2: 1
Chain
drive and OHC with rocker arm
- 5° BTDC
"35° ABDC
35° BBDC'
- 5° ATDC
Forced pressureand wetsurnp
Trochoid
Air cooled
. Paperfilter
"Assembled type
38.5 kg (84.9Jbs)
Vertical twin, paral1el
-;~;

CB250 Addendum
G I (C td)
-
enera
on
,
Item
Specifications
Carburetor
Carburetor tvpe
Constant Velocity single carburetor
Throttlé bore
26mm (1.0 in)
Drive Train
Clutch system
Multi-plate, wet
Clutch operation system
Mechanical type
Transmission
5 speeds
Primaryreduction
3.631 (69/19)
Secondary reduction
---
Third reduction ---
Final reduction
2.214 (31/14)
Gear ratio 1st 2.846 (37/13)
Gear ratio 2nd
1.777 (32/18)
Gear ratio 3rd 1.333 (28/21)
Gear ratio 4th 1.083 (26/24)
Gear ratio 5th 0.913 (21/23)
Gear ratio 6th
---
Gear ratio reverse ---
Gearshift pattern Left foot operated, return system, 1- N - 2 - 3 - 4 - 5
Electrical ... Ignition system
CDI
Starting system
Electric starter
Charging sy.stem Tripple phase output type
Regulator/rectifier type
SCR shorted tripple phase, full-wave rectification
Lighting system Alternator
AC regulatortype ---
(

CB250 Addendum
Lubrication
Unit: mm (in:
Item
Standard Service limit
Other viscosities shown in the chartmay
be used when the average temperature in
your riding area is within the indicated
range.
1.5 e (1.6US qt. 1.3 Imp qt)
1.8 e(1.9 US qt, t.s.lmp qt)
Use Honda 4-stroke Oil or equivalent
API Service Classífication: SE, SF or SG
Viscosity: SAE 10W - 40
01020304.O"C
I
5On%e '
,,, .... I
i
~Imm
Engine oil capacity at draining
at disassembly
at oil filter change
Recommended engine oil
20 40 lKl 80
Oil pressure at oil pressure switch
Oil pump rotor tip clearance CD
body c1earance ®
end clearance ®
0.15 (0.006)
0.15 - 0.18 (0.006 - 0.007)
0.03 - 0.11 (0.001 - 0.004)
0.20 (O.OOS)
0.25 (0.010)
0.14 (0.006)
r- Fuel System
Carburetor identification number
Main jet
VE37E
#105
(High altitude)
(2,3)
(1, 4)
(Front)
(Rear)
Slow jet
Jet needle clip position
Pilot screwinitialopening.
Pilot screw high attitudeadjustrnerrt
Pilot screw final opening
Air screw initial opening
. Air screw high altitude adjustment
Float level
Carburetorvacuurn difference
!Base carburetor (For carburetor synchronization)
Idle speed
Throttle grip free play
Accelerator pump clearance
Secondary air supply svstern
Air injection control valve vacuum pressure
Carbur etor he ater resistance
#40
1-5/8
1/4 tu rns
out
lS.5 (0.73)
1,500 ±
TOO min-'(rpm)
2 - 6 (l/S- 1/4)
I
1Q .11

CB25D Addendum
Lubrication
Item
Engine oil capacity at draining
at disassembly
at oil filter change
Recommended engine oil
20 40 80 80
Oil pressure at oil pressure switch
Oil pump rotor tip clearance CD
body c1earance ®
end clearance CID
Standard
1.5 e (1.6US ot. 1.3 Imp qt)
1.8 e(1.9 US qt, 1.S.lmp qt)
Use Honda 4-stroke Oil or equivalent
API Service Classification: SE, SF or SG
Viscosity: SAE 10W - 40
Other viscosities shown in the chartmay
be used when the average temperature in
your riding area is within the indicated
ranqe.
0.15 (0.006)
0.15 - 0.18 (O.OOS - 0.007)
0.03 - 0.11 (0.001 - 0.004)
Unit: mm (ir
Service Limit
0.20 (0.008)
0.25 (0.010)
0.14 (0.006)
~ Fuer System
Carburetor identification number
Main jet
(High altitude)
(2,3)
(1, 4)
(Front)
(Re ar)
Slow jet
Jet needle clip position
Pilot screwinitialopening.
Pilot screw high altitudeadjustment
Pilot screw final openinq
Air screw initial opening
. Air screw high altitude adjustment
Float level
Carburetorvacuurn difference
Base carburetor (For carburetor synchronization)
Idle speed
Throttle grip free play
Accelerator pump clearance
Secondary air supply system
Air injection control valvevacuum pressure
Carburator heater resistance
1Q Ji
VE37E
#105
#40
1-5/8
1/4
turns out
18.5 (0.73)
1,500 ±100
rnirr lIrprrrl
2 - 6 (1/8- 1/4)
13 - 15 n(20°C/68°F)

CB25D Addendun
Unit: mm (in
Cylinder Heacl -----~~----_._--------------___,__------:.-
Item Standard Service Limit
Cylinder com pression
{kPa (kgf/cm
2,psi)/500 - 600
min-
1(rprnl)
Cylinder compression difference
{kPa (kgf/cm
2,psi)/500 - 600
mirr ' (rprnl}
Valve clearance IN
EX
Cylinder head warpage
Cam lobe height CD IN
EX
Camshaft runout
Camshaft oil clearance A
B
1,373 - 1,471 (14 - 15,199 - 213)
98 (1,14)
0.06 - 0.10(0.002 -0.004)
0.06 -0.10·(0.002 -0.004)
27.383..c 27.543 (1.0781 - 1.0844)
27.209 -27.369 (1.0712 -1.0775)
785 (8, 114)
0.10 (0.004)
27.2 (1.07)
27.0(1.06)
0.05 (0.002)
OJCD
Camshaft journal 0.0. A
B
Camshaft bushing 1.0.
Carnshaft holder 1.0. A
B
Va/ve stem 0.0. IN
EX
Valve
guide 1.0. IN
EX
Stem-to-guide clearance IN
EX
Valve guide pr ojection aboye cylinder head IN
EX
Before guide installation:
1. Chill the valve guides in the freezer section of
the refrigeratorfor about an hour
- 2. Heat the cylinder head to
100 - 150°C (212 - 300°F)
.Valve
seat width
Vert\re sprin'g free length IN
EX
inner IN
inner EX
outer IN -.
outerEX
Rocker arm 1.0. IN
EX
Sub-rocker arm 1.0. IN
EX
RockerarmshaftO.D. IN
EX
Sub-rocker arrn shaft 0.0. IN
EX
Rocker
arrn-to-rocker arrn shaft clearance
Sub-rocker arrn-to-rocker arrn shaft clearance
Valve lifter 0.0.
Valve lifter bore 1.0.
Hydraulic lash adjuster assist spring freelength
Hydrauliclash adjuster compression stroke with
kerosene
19.967 -19.980 (0_7861 - 0.7866)
20.063 -20.083 (0.7899 -0.7907)
5.450 - 5.465 (0.2146 -0.2152)
5.430 - 5.445 (0.2138 -0.2144)
5.475 - 5.485 (0.2156 -0.2159)
5.475 - 5.485 (0.2156 -0.2159)
0.010- 0.035 (0.0004 -0.0014)
0.030
-0.055 (0.0012 -0.0022)
1.0 - 1.1 (0.039 - 0.043)
29.9 (1.18)
29.9 (1.18)
38.2 (1.50)
38.2(1.50)
1 Q.OOO -10:015 (0.3937 -0.3943)
10.000.., 10.015 (0.3937 -0.3943)
9.978 - 9.987(0.3928 -0.3932)
9.978 - 9.987 (0.3928 -0.3932)
0.013:- 0.037 lO.0005 -0.0015)
19.92 (0.784)
20.20 (0.795)
5.42 (0.213)
5.40 (0.213)
5.50 (0.217)
5.50 (0..
;217)
0:08 (0.003)
0.10 (0.004)
1.8 (0.07)
29.0 (l.14)
29.0(1.14)
37.0 (1.46)
37.0 (1.46)
10.10 (0.398)
10.10 (0.398)
. 9.91 (0.390)
9.91 (0.390)
0.05 (0.002) ..
19-5

CB25ü Addendum
Cvlinder/Piston
Item
Cylinder I.D.
out of round
taper
warpage
Piston mark direction
Pisto n O.D. (O)
Piston O.D. measurement point (H)
Piston pin hole I.D. (d)
(d)
Cylinder-to-piston clearance
Pisten pin O.D.
Piston-to-piston pin clearancé
Connectinq rod-to-piston pin clearance
Top ring-to-ring groove clearance
Second ring-to-ring groove c1earance
Top ring end gap
Second ring end gap
Oil ring (side rail) end gap
Top ring mark
Second ring mark
-Crankshaft
Connecting rod small end I.D.
Connecting rod bigendside clearancs
radial clé arance -
Crankshah runout (at both ends) G)
(at bearing holder) @
bG)
39.5 mm
(1.56 in)
U .
IJ l'9.5 mm
(0.37 in)
Crank pin oil clearance
Crank pin bearing selection
Main journal oil clearance
Main journal bearing selsction
Standard
53.000 - 53.010 (2.0866 - 2.0870)
"IN" mark facing toward the intake side
52.970 - 52.990 (2.0854 - 2.0862)
10 mm (0.4 in) from the bottom
15.002 - 15.008 (0.5906 - 0.5909)
0.010 - 0.040 (0.0004 - 0.0016)
14:994 - 15.000 (0.5903 - 0.5906)
0.002 - 0.014(0.0001 - 0.0006)
0.016 - 0.040 (0;0006 - 0.0016)
0.015 - 0.040 (0.0006 - 0.0016)
0.015 -0.040(0.0006 - 0.0016)
0.15 - 0.30 (0.006 -0.012) .
0.30 -0.45 (0.012 -0.018)
0.2 - 0.7 (0,01 - O.03)
"N".mark side facing up
"N" markside facing up
15.016 - 15.034 {0.59 J2 - 0.5919)
0.10-0.40 (0.004-0.016)
0,004 - 0.012 (0.0002 - 0.0005)
.""
Unit: mm (in)
Service Limit
53.10 (2.091)
0.05 (0.002)
0.05 (0.002)
0.05(0.002)
52.90 (2.083)
15.05 (0.593)
0.10 (0.004)
14.98 (0.590)
0.07 (0.003)
0.10 (0.004)
0.10 (0.004)
0.10 (0.004)
0.45(0.018)
0.60 (0.024)
0.90 (0.036)
15.08 (0.594)
0.6 (0;02)
0.05 (0.002)
0.03 (0.001)
0.05 (0.002)
..
-Kickstarter --------'--------'-------,-----------~----~-,------
Kickstarterpinion gear I.D.
Kickstarter spindle O.D.
Kickstarter id le gear I.D.
Countershah O.D. at kickstarter id le gear
Kickstarter idle gearbushing O.D.
I.D.
19-6

Transrnrssion
Item
Transmission gear I.D. M5
Cl
C4
Transmission gear bushing O.D. Cl
Transmission gear bushing I.D. el
Gear-to-bushing clearance at Cl gear
Mainshaft O.D. at M5 gear
at c1utch outer guide G)
Countershaft O.D. at Cl gear
at C4 gear
Gear-to-shaft clearance at M5 gear
at C4 gear
Gear bush ing-to-shaftclearance al Cl gear
Shift fork claw thickness L
C
R
Shift fork I.D. L
C
R
Shift fork shaft O.D. L
C
R
Shift drum O.D.
Standard
20.020 -20.041 (0.7882 -0.7890)
20.020 -20.041 (0.7882 -0.7890)
20.020 -20.041 (0.7882 -0.7890)
19.979- 20.006 (0.7866 -0.7874)
16.516 - 16.534 (0.6502 -0.6509)
0.020 -0.062 (0.0008 -0.0024)
19.959
-19.980 (0.7858 -0.7866)
19.959
-19.980 (0.7858 -0.7866)
16.446 -16.484 (0.6475 -0.6490)
19.959
-19.980 (0.7858 -0.7866)
0.040 -0.082 (0.0016 -0.0032)
0.040 -0.082 (0.0016
-0.0032)
0.032 -0.068 (0.0013 -0.0027)
4.93 -
5.00(0.194 - 0.197)
4.93 -5.00 (0.194 - 0.197)
4.93 - 5.00 (0.194 -0.197)
12.000 - 12.018 (0.4724 -0.4731)
12.000 -12.018 (0.4724 -0.4731)
12.000 -12.018
(0.4724-0.4731)
"'"19 :976"'; 11.994 (0.4715 -0.4722)
11.976 -
11.994 (0.4715 -0.4722)
11.976 - 11.994 (0.4715 -0.4722).
CB250 Addendum
Unit: mm (in)
Servica Umit
20.08 (0.791)
20.08 (0.791)
20.08 (0.791)
19.93(0.785)
16.58 (0.653)
0.10(0.004)
19.91 (0.784)
19.91 (0.784)
16.41 (0,646)
19.91 (0.784)
0.10(0.004)
0.10 (0.004)
0.10 (0.004)
4.80 (0.189)
4.80 (0.189)
4.80 (0.189)
12.05 (0.474)
12.05 (0.474)
12.05 (0.474)
11.93 (0.470)
11.93 (0.470)
11.93 (0.470)
19-7

Unit: mm (in)
r- Cfutch System
Item
Standard
Service Limit
Clutch lever free play 10 - 20 (3/8 ~ 3/4)
---
Recornrnended clutch fluid
--- ---
Clutch master cylinder I.D.
---
---
Clutch master piston O.D.
--- ---
Clutch outer I.D.
26.000 - 26.012 (1.0236 - 1.0241)
26.04 (1.025)
Clutch outer guide O.D.
25.959 - 25.980 (1.0220 - 1.0228)
25.90 (1.020)
I.D.
20.000 - 20.021 (0.7874 - 0.7882)
20.05 (0.789)
Mainshaft O.D. at ciutch outer guide
--- ---
Clutch spring free heigJ;ot:"
--- ---
Clutch spring free length
37.~ (1.49)
36.0 (1.42)
Clutch disc thickness
2.8 - 2.9 (0.11 - 0.15)
2.6 (0.10)
Clutch disc thickness A
--- ---
B
--- ---
Clutch plate warpage
---
0.20 (0.008)
Centrifugal clutch drum I.D.
---
---
bushing O.D.
---
---
Centrifugal clutch center guide I.D.
---
---
0.0.
---
---
Centrifugal clutch center guide collar.heiqht
--- ---
Centrifugal clutch weight lining thickness
---
---
Centrifugal clutch spring free length
---
---
Clutch lining thickness
---
---
Crankshaft O.D. at clutch center ---
~.
---
~
CoolingSystem
Coolant capacito y_ (Radiato.r and engine)
(Reserve tank)
Radiator cap relief pressure
Thermostat begin to open
I Thermostat fully open
. Thermostat valva lift
- Drive Train
Recommended final drive oil
Final
drive gear oil capacity at disassembly
at draining
Final drive gear backlash
Final
drive gear backlash difference between
measurement
Ring gear-to-stop pin clearance (A)
Stop pin shim
Ring gear spacer
Pinion spacer
Final drive gear assembly preload
Output gear backlash
Output gear I.D.
Output gear bushing 0:0.
I.D.
Output drive shaftO.D.
Output geardamper spring free length
Output shaft adjustment shirn
Countershaft drive shaft adjustment shim
19-8

CB250 Addendum
Unit: mm (in)
- Wheels/Tires
Item
Standard Service Limit
Minimum tire thread depth (FR)
---
1.5 (0.06) I
(RR)
---
2.0(0.08)
I
Cold tire pressure Up 1'090 kg (200 lb) load (FR) 200 kPa(2.00 kgf/cm
2,29 psi)
---
Up 1'090 kg (200 lb) load (RR) 200 kPa (2.00 kqf/crn", 29 psi) ---
Up 1'0 maximum weight capacity (FR) 200 kPa(2.00 kgf/cm
2,29 psi)
---
Up 1'0 maximum weight capacity (RR) 200 kPa (2.00 kgf/cm
2,29 psi)
---
,
Front and rear axle runout
0.2 (0.01)
Front and rear wheel rirn runout (Radial)
---
2.0 (0.08)
(Axial) ---
2.0 (0.08)
Front wheel hub-to-rirn distance
,
---
---
Front wheel hub standard surface
---
----
Rear wheef hub-to-rim distance
---
---
I
Rear wheel hub standard surface
I
---
---
,
Wheel balance weight (Front)
---
609 (2.1 oz)max.
(Rear)
---
609 (2.1 oz) max.
Orive cha in slack
20 - 30 (3/4 - 1-1/4)
---
,
Orive chain size/link (010) 520VC.6-106LE ---
\
(RK)
520MO-Z9-106LE ---
r-r-' Front Suspension
Fork spri ng free length
Fork spring free length A
8
Fork spring direction
Fork tube runout
Recommended fork oil
Fork oil level
Fork oil level (R)
(U
Fork oil capacity
Fork oil capacity (R)
{U
_ Fork air pressure
Steering bearing preload
59.7 (2.35)
488.7 (19.24)
Tightly wound coil facing down
Forkfluid
162 (6.4)
150
cm" (5.1 US oz, 5.3 Impoz)
0.1 - 0.15 kgf-m
58 (2.3)
479 (18.86)
0.2 (0.01)
r-r- 'Rear Suspension
Shock absorber spring free length
Shock absorber spring free leriqth (A)
(8)
Oamper gas pressure
Oamper compressed gas
Oaniper rod compressed force at 10 mm (0.4 in)
compressed
Oamper driUing point
Shock absorber spring installed length
(Standard)
(Adjustable range)
Shock absorberspríng adjuster standard position 2nd groove
Shock absorber spring direction
Recommended shock absorber oil
Shock absorber oil capacity
air pressure
19-9

CB250 Addendum
Unit: mm (in)
Brakes ---------------....-------~-----------,....-----~-.-:.
Item
Standard
Service Limit
Front brake fluid
brake lever free play
brake pad wear indicator
DOT 3 or DOT 4
10 - 20 (3/8 -
314)
.To the groove CD
CD
brake disc thickness
brake disc runout
master cylinder 1.0.
master piston 0.0.
caliper cylinder 1.0.
caliper cvlinder 1.0. (Upper).
(Lower)
caliper piston 0.0.
caliper piston 0.0. (Upper)
(Lower)
brake drum 1.0.
brake Iining thickness
Rear brake fluid
brake pedal height
brake pedal free play
brake pad wear indicator
.. If0í
~ J01?" ,':1
/ ,')<~~~j
brake disc thickness
brake disc runout
master cylinder 1.0.
master piston 0.0.
caliper cylinder 1.0.
caliper piston 0.0.
brake drum 1.0.
brake lining thickness
4.0 (O.16)
11.0 - 11.043 (0.4331 - 0.4348)
10.957
-10.984 (0.4314 -0.4324)
27.000 -27.050 (1.0630 - 1.0650)
26.918 -26.968 (1.0598 -1.0617)
20 - 30 (3/4 -1-1/4)
130 (5.1)
4.0 (O.16)
3.5 (0.14)
0.30 (0.012)
11.05 (0.435)
10.95 (0.431)
27.06 (1.065)
26.91 (1.059)
131 (5.2)
2.0 (0.08)
r-r- Battery/Charging System
Alternator chargingcoil resistance (At 20°C/68°F)
Regulator/rectifier regulated voltaqe/arnperaqe'
Battery capacity
Battery specific gravity (Fullv charging)
(Needs charging)
Battery chargíng rate (Normal)
(Quick)
Battery voltage (Fully charged 20°C!68°F)
(Needs charging 20°C/68°F)
Alternator lightingcoil resistance (At 20°C/68°F)
. AC regulator regulated voltage (With analog type)
(With digital type)
0.2 - 0.6 n
13.5 -14.0 V/1 A
12 V - 6 Ah
0.6A/10h
3 A/1.0 h
13-13.2V
Below 12.3 V

CB250 Addendum
i!
,\
Unit: mm (in)
s
St tO
r-
ar mg
ystem
Item
Standard
Service Limit
Starter driven sprocket 1.0. 22.010- 22.022 (0.8665 - 0.8670) 22.08 (0.869)
Starter driven sprocket boss 0.0.
36.975 - 37.000 (1.4557 - 1.4567)
, 36.90 (1.453)
Starter driven gear '1.0.
'---
---
Starter clutch outer 1.0.
---
---
Starter motor brush spring tension
780 -1,060 9450 9
brush length 12.5 -13.0 (0.49 -0.51) 8.5 (0.33)
- Ignition System
Spark plug (Standard)
(For cold climate/below 5°C/41°F)
(For extended high speed riding)
Spark plug gap
Ignition timing "F" mark
Advance start
stop
Full advance
Peak voltage Ignition coilIf'rirnarv side)
Exciter coil
PuIse generator coil
Alternator exciter coil resistance (At 20°C/68°F)
Ignition coil resistance (Prirnarv: at 20°C/68°F)
(Secondary with plug cap)
(Secondary without plug cap)
Pulse generator resistance (At 20°C/68°F)
CR6HSA (NGK)
U20FSR-U (NIPPONOENSO)
CR5HSA (NGK)
U16FSR-U (NIPPONDENSO)
CR7HSA (NGK)
U22FSR-U (NIPPONDENSO)
0.60 - 0.70 (0.024 - 0.028)
10
0BTDC/1,500min-'
(rpm)
10°/1,700 min-' (rpm)
25°/3,000min-
1
(rpm)
25°/3,000 min-' (rprn)
100 V rninimurn
100 V minimum
0.7V mínimum
50-1800
0.1-0.30
6.5 - 9.7 kO
2.8 - 3.4 kO
50 - 170 O
Lights/Meters/Switches
Main fuse
Fuse
Headlight (high/low beam)
Tail/brake light
License light
Position light
Front turn signal/running light
Front turn signallight
Rear turn signal light
Instrument lights '.
Oil pressure warning indicator
Tail/brake light warning indicator
Side stand warning indicator
Low fuel indicator
Co olant temperature indicator
Oil temperature indicator
High beam indicator
Tu rnsig n ali ndicator
Neutral indicator
Reverse indicator
Overdrive indicator
Oil temperature sensor resistance
Fuel uriit resistance (At fu" level)
(At low level)
Fuel pumpflow capacity (min./minute)
Coolant temperatúre sensor resistance (AtOC¡OFj
Fan
motor switch starts (ON)
stops (OFF)
20A
10 Ax2
12V-45/40W
12 V - 5/21 W
12 V - 4 W (E
type only)
12V-21Wx2
12V-21 Wx2
12 V - 3.4 W x2
12V-l.7W
12V-3.4W
12 V - 3.4 Wx 2
12 V - 3.4 W
19-11

CB250 Addendum
Torque Values
r-r-: Standard
Fastener Type
Torque
Fastener Type
Tarque .
N'm [kgf-m, Ib-ft)
N'm (kgf'm, Ib-ft)
5 mm hex bolt and nut
5 (0.5, 3.6) 5
mm screw
4 (0.4, 2.9)
6
mm hex bolt and nut
10 (1.0, 7) 6
mm screw
9 (0.9, 6.5)
8
mm hex bolt and nut
22 (2,2, 16) 6
mm flange bolt (8 mm head)
9 (0.9, 6.5)
10
mm hex bolt and nut
34(3.5, 25} 6 mm flange bolt (10 mm head) and 12 (1.2, 9)
12
mm hex bolt and nut
54 (5.5, 40)
nut
8 mm flange bolt and nut
26 (2.7, 20)
1°
mm flange bolt and nut 39 (4.0, 29)
Torque specifications listed below are for important fasteners. Others should be tightened to standard torque values listed
aboye.
NOTE 1.· Apply sealant to the threads.
2. Applya locking agent to the threads.
3. Apply molybdenum disulfide oil to thethreads and flange surface.
4. Left hand threads.
5. Stake.
6.
Apply oil to the threads and flange surface.
7. Apply clean engine oil to the O-ringo
8.
Torque wrench scale reading usinga special tool.
9. Apply grease to the threads and flange surface.
10. UBS bolt.
11.U-nut.
12. Alock bolt. Do not reuse.
E
r--
ngme
I
Item
O'tv
Thread dia. Tarque
Remarks
(mm)
N'm (kqf-rn, Ib-ft)
.,
Lubrication System:
Oil pump mounting screw
3610 (1.0, 7)
Cylinder Head/Cvlinder:
Spark plug
210
12(1.2,9)
Va/ve adjusting lock nut
I
45¡
10(1.0,7)
Cylinder head/camshaft holder nut 88I23 (2.3, 17)
Cvlinder head bolt 3 6 i12 (1.2, 9)
Cam sprocket bolt 2 7 20 (2.0, 14)
Note 2
Cylinder h~d cover bolt 26,10 (1.0, 7)
Clutch/Gearshift Linkage:
Clutch lifter bolt
46
12(1.2,9)
Clutch center locknut
116 74
(7.6,55)
Note 5, 6
Shift drum stopper arm bol! .I16 12(1.2,9)
Gearshift return spring pin
18
25(2.5,18)
Note 2
Primary drive gear lock nut
116 53 (5.4, 39)
Crankcase/Cran kshaft:
A
Drive sprocket bolt
2 6
12(1.2,9)
Oil drain bolt
112 25 (2.5, 18)
Crankshaft mounting bolt
5823 (2.3, 17)
Crankshaft mounting nut 1612 (1.2, 9)
Oil
passage plate mounting screw
36
10(1.0,7) Note 2
Starter Clutch/ Alternatar:
Flywheel bolt
110 59 (6.0, 43)
Starter clutch mounting screw
369 (0.9, 6.5)
Note 2, 5
Stator mountíng screw
35I6 (0.6, 4.3)
Stator wire clamp screw
15I6 (0.6, 4.3)
Pulse
generator mounting screw
2610 (1.0, 7)
Starter motor terminal nut
166 (0.6, 4.3)
19-12

CB250 Addendum
F
r-r-'
rame
.
Thread día.
Torque
,i
ltern
Q'ty
Remarks
Lo.
(mm)
N·m (kqf-rn, Ib-ft)
Front Suspension:
L
Steering stem nut
1 22 74 (7.5, 54)
Steering stem adjustment nut
1 22 3(0.3, 2.2)
;~
Handlebar holder bolt 4o' 824
(2.4,17)
Fork top bridge pinch nut
2822 (2.2, 16)
Note 11
Fork bottom bridge pínch bolt
2 8 24 (2.4, 17) 1'-
Steering lock mounting bott
2 6 9(0.9, 6.5) Note 2
Fork cap
2 27 23 (2.3, 17)
Fork socket bolt
2820
(2.0,14)
Note 2'1
i
Rear Suspension:
'-
Swingarm pivot nut
114 59 (6.0, 43)
Note 11
Rear shock absorber lower mounting bolt 210 42
(4.3,31)
Wheels:
Front axle nut
114 59
(6.0,43)
Note 11
~
Rear axle nut
114 59
(6.0,43)
Note 11
Brake arm torque link bolt
2822
(2.2,16)
~
Driven sprocket nut 410 44 (4.5, 33)
Note 11
Brake system:
Pad pin plug
1 8 3
(0.3,2.2)
"i
Pad pin
1818 (1.8, 13) ". o'
Caliper pin bolt (bracket side)
1 8 13
(1.3,9)
Note 2
t-
(caliperside)
1 8 23 (2.3, 17)
Note 2
Caliper bleed valve
166
(0.6,4.3)
Frorit caliper mounting bolt
30 (3.1, 22) I
210 I
Brake disc bolt
4 8 42
(4.3,31)
"-
Master cylinder reservoir cap screvv 2I42(0.2, 1.4)
Brake hose oil bolt
2la
34 (3.5, 25) J
Brake lever pivot nut
166(0.6, 4.3) l1
o, ....
Rearbrake arm pinch bolt
1610 (1:0, 7)
Other Fasteners:
L
Engine rear mounting bolt
2 10 83 (8.5,
61)
Exhaust pipe joint nut
46I14
(1.4,10)
Side stand switch mounting bolt
1 6 29
(3.0,22)
Note 12
~J
Side stand bracket bolt
2i836 (3.7, 27)
,ti

CB250 Addendum
Lubrication & Seal Points
E
~
ngme
Location
Material
Remarks
Rocker arm and shaft sliding surface Engine oil
Cam Chain
Transmission gear teeth and bushings
Piston pin hole
Piston pin surface
Connecting rod small end
Each bearings
Piston ringsliding surface
Piston ring and ring groove
Crankshaft big end
Shift fork claw and pivot inner surface
Shift drum
Clutch discs
Clutch center lock nut threads
Valve stem (valve guide sliding surface) Molybdenum disulfide oil
Valve guide (valve stem slidinq surface) (a mixture of 1/2 engine
Camshaft bushing inner surface oil and 1/2 molybdenum
Cam lo bes disulfide grease)
M3, 4 gear spline
Cl gear, Cl bushing sliding surface
M4, C3, C5 shift.fork grooves
Oil passage plate screw threads
..
Locking agent
F
~
rarne
Location
Material
Remarks
..
Steering stern bearing
Multi-purpose grease
Wheel bearing .
Brake lever pivot boltsurface
Clutch lever pivot bolt surface
Wheel bearing dust seallips
Wheel axle outer surface
Applythin coat of grease
Handlebar (throttle grip sliding surface)
Throttle cable end
Side stand pivot surface
Center standpivot surface
Dust seal lips
Fork socket bolt
Locking agent
Forkcap O-ring
Fork fluid
Fork oil seallips
Handle grip
Honda Bond A or
"-
equivalent
./
19-14

Cable & Harness Routing
(7)
CARBURETOR
HEATER WIRE
(15) PULSE GENERATOR
CONNECTOR
(14) SIDE
STAND SWITCH
CONNECTOR
CB250 Addendum
(1) CARBURETOR HEATER CONNECTOR
___ (2) CARBURETOR
~ HEATER WIRE
r
Q ~ ( 3 } S I D E STA~D
'=-V . SWITCH WIRE
. (4) ALTERNATOR WIRE
(5) PULSE GENERATOR WIRE
/
(/
(9)
CARBURETOR
AIR VENT
TUBE
(10) GROUND CABLE
19-15
j
i
'-
I
'-
L

CB25D Addendum
(3) STARTER MOTOR CABLE
(5) SIDE STAND SWITCH WIRE (3) STARTER MOTOR CABLE
(6)
CAR'BURETOR DRAIN TUBE
(M AIR/OIL SEPARATOR DRAIN TUBE
~ ~
0\--------1 ----l.,)...~-~ o'g1r
19-16

CBZ50 Addendum
Carburetor Removal/lnstallation
Gasoline is extremely flammable and is explosive under certain conditions.
Work in well ventilated area. Smoking or allow flames or sparksinthe working area or wheregasolineis stored can
cause a fire or explosion.
NOTE
Before removal, turn the fuel valve OFF.
Route the tubes and wires properly (page 19-15).
Requisite Service
I
'-
Rear fairing removal/installation (page 2-3)
Fuel
tank removal/installation (page 2-4)
Carburetor draíning
Procedure
I
Q'ty·
Remarks
Removal Order
lnstallation is in the reverseorder of removal
(1)
Carburetor heater 2P connector 1
'"
(2)
Wire barid/Clurnp
1/1
(3)
Clutch cable
1
(4)
Th rottle cables
2
(5)
Choke cable
1
(6)
Drain tube
1
(7)
Carburetor mounting nut
2
(8)
Connecting tube band screw 1
Onlyloosen.
(9)
Carburetor assembly 1
..
(10)
O-ring 1
(11)
Gasket
~.-
1
19-17

CB25ü Addendum bly/Assembly
.. sem __
Carburetor Dlsas .
(3)
(1)
I
. -(8)
1(9) A
~
(4)
(11 )
19-18