Yamaha XS650H 1978 Manual

INDEX
This manual has been combined with previous
service manuals to provide complete service
information for: XS650H/SH.
Please read and give special consideration to
the “NOTICE” on the preceding page for your
safety.
XS650H/SH SUPPLEMENT
XS650 MODELS 1978-80

FOREWORD
This Supplementary Service Manual has been prepared to introduce new
service and new data for the XS650H/XS650SH. For complete information
on service procedure, it is necessary to use this Supplementary Service
Manual together with following manuals:
’ XS650E Service Manual (LIT-11616-00-76)
I
!
’
XS650SE Supplementary Service Manual (LIT-11616-01-08)
XS650SF/2F Supplementary Service Manual (LIT-11616-01-65)
1
XS650G/SG Supplementary Service Manual (LIT-1 1616-01-75)
SERVICE DEPT.
INTERNATIONAL DIVISION
YAMAHA MOTOR CO., LTD.
NOTE:
This Supplementary Service Manual contains information regarding periodic
maintenance to the emission control system for the
XS650H/XS650SH.
Please read this material carefully.
NOTICE
This manual was written by the Yamaha Motor Company primarily for use
by Yamaha dealers and their qualified mechanics. It is not possible to put
an entire mechanic’s education into one manual, so it is assumed that
persons using this book to perform maintenance and repairs on Yamaha
motorcycles have a basic understanding of the mechanical concepts and
procedures inherent to motorcycle repair technology. Without such know-
ledge, attempted repairs or service to this model may render it unfit for use
and/or unsafe.
This model has been designed and manufactured to perform within certain
specifications in regard to performance and emissions. Proper service with
the correct tools is necessary to ensure that the motorcycle will operate as
designed. If there is any question about a service procedure it is imperative
that you contact a Yamaha dealer before continuing. Before attempting any
service, check with your Yamaha dealer for any service information changes
that apply to this model: This policy is intended to provide the customer
with the most satisfaction from his motorcycle and to conform with federal
environmental quality objectives.
Yamaha Motor Company, Ltd. is continually striving to further improve all
models manufactured by Yamaha. Modifications and significant changes in
specifications or procedures will be forwarded to all Authorized Yamaha
dealers and will, where applicable, appear in future editions of this manual.
I -

Particularly important information is distinguished in this manual by the
following notations:
NOTE
:
A NOTE provides key information to make procedures easier
or clearer.
CAUTION: A CAUTION indicates special procedure that must be fol-
lowed to avoid damage to the motorcycle.
WARNING: A WARNING indicates special procedures that must be fol-
lowed to avoid injury to a motorcycle operator or person
inspecting or repairing the motorcycle.
Starting Serial Number
XS650HH
. . . . . . . . . . . . . 4N9-000101
XS650SHH
. . . . . . . . ..__. 4M4-000101

MAINTENANCE AND LUBRICATION CHART
PERIODIC MAINTENANCE EMISSION CONTROL SYSTEM
-3

t
c
c

*ENGINE
A. IGNITION TIMING
The ignition system is modified for easier
maintenance. Thus, the following “ignition
timing check” should be changed,
Ignition timing check
1. Ignition timing is checked with a timing
light by observing the position of the
rotor pointer and the marks stamped on
the timing plate.
The timing plate is marked as follows.
“ll” Firing range for No. 1 (L.H.)
“T” Top Dead Center for No. 1,
fL.H.1 cylinder
2. Connect the timing light to the left
cylinder spark plug lead wire.
3. Start the engine and keep the engine
speed as specified. Use a tachometer to
check the engine speed.
B. PICK-UP COIL ASSEMBLY
The method of mounting the pick-up coil
assembly is changed for easier service work.
Thus, the followings “Pick-up coil assembly
removal” and “Pick-up coil assembly reinstal-
lation” should be changed.
Pick-up coil assembly removal
Remove the pick-up coil securing screws and
remove the pick-up coil
assembly.
Pick-up coil assembly reinstallation
Install the pick-up coil assembly on to the
stator assembly.
_ L
4.
Specified engine speed:
1,200 r/min
The rotor pointer should be within
the limits of
” fl ”
on the timing plate.
If it exceeds the limits or does not
steady, check the timing plate for tight-
ness and/or ignition system for damage.
NOTE:
Ignition timing is not adjustable.
C. FUEL LEVEL
The carburetor is furnished with a drain screw
to provide easy access to service work. Thus,
the following “Fuel level measurement”
should be added.
Fuel level measurement
NOTE:
Before checking the fuel level, note the follow-
ing:
1. Place the motorcycle on a level surface.
2. Adjust the motorcycle position by plac-
ing a suitable stand or a garage jack
under the engine so that the carburetor
is positioned vertically.
1.
2.
Connect the level gauge (special tool) or
a vinyl pipe of 6 mm (0.24 in) in inside
diameter to the float bowl nozzle left or
right side carburetor.
Set the gauge as shown and loosen the
drain screw.
-5

3. Start the engine and stop it after a few
minutes of run. This procedure is
neces-
sary to obtain the correct fuel level.
NOTE:
Make sure the fuel petcock is “ON” or “RES”
oosition.
4.
Note the fuel level and bring the gauge
to the other end of the carburetor line
and repeat step 3 above. Note the fuel
level again and compare it with the
previous gauge reading. They should be
equal. If not, place a suitable size of
wooden piece or the. alike under the
center stand and adjust.
5. Check the fuel level one by one. The
level should be in the specified range.
Fuel level:
1 f 1 mm (0.04? 0.04 in) above
from the carburetor mixing chamber
body edge.
YL___-A
6. If the fuel level is incorrect, remove the
carburetor assembly from the motor-
cycle and check the fuel
valve(s) and
float assembly(s) for damage.
7. If no damage is found, correct the fuel
level by slightly bending the float arm
tang. Recheck the fuel level.
D. ENGINE OIL LEVEL MEASUREMENT
1.
Place the motorcycle on the center stand.
Warm up the engine for several minutes.
NOTE:
Be sure the motorcycle is positioned straight
up when checking the oil level; a slight tilt
toward the side can produce false readings.
-6-
Y

2 With the engine stopped, check the oil
level through the level window located at
the lower part of the right side crankcase
cover, or screw the dip stick completely
out and then the stick in the hole.
NOTE:
Wait a few minutes until the oil level settles
before checking. When checking engine oil
level with the dip stick, let the unscrewed dip
stick rest on the case threads.
1. Dip stick
2. Maximum level 3.
Minimum level
3. The oil level should be between maxi-
mum and minimum levels. If the level
is lower, add sufficient oil to raise it to
the proper level.
l-

*CHASSIS
A. REAR WHEEL REMOVAL
1. Place the motorcycle on the center stand.
2. Remove the tension bar and the brake
rod from the brake shoe plate. The ten-
sion bar can be removed by removing the
cotter pin and nut from the tension bar
bolt. The brake rod can be removed by
removing the adjuster.
1. Adjusfer
2. Brake rod 3. Tenrio” bar
3. Disconnect the drive chain.
4. Loosen the chain tension adjusting nuts
and bolts on both sides.
5. Remove the axle nut cotter pin and axle
nut. Discard the old pin.
6.
7.
a.
Remove the axle shaft and the wheel.
For reassembly, follow the procedure
below with care:
Make sure the drive chain master link is
correctly installed with rounded end in
direction of chain travel.
b. Make sure the axle nut is properly
torqued and a new cotter pin is installed.
15.0 m-kg (108.5 ft-lb)
c. Adjust the drive chain.
8. DRIVE CHAIN TENSION CHECK
NOTE:
Before checking and/or adjusting, rotate rear
wheel through several revolutions and check
tension several times to find the tightest
point. Check and/or adjust chain tension
with rear wheel in this “tight chain” position.
Inspect the drive chain with the center stand
put up. Check the tension at the position
shown in the illustration. The normal vertical
deflection is approximately 20
- 30 mm (0.8
- 1.2 in). If the deflection exceeds 20 - 30
mm (0.8 - 1.2 in) adjust the chain tension.
C. DRIVE CHAIN TENSION ADJUSTMENT
1. Loosen the rear brake adjuster.
2. Remove the cotter pin of the rear wheel
axle nut with pliers.

NOTE:
The rear wheel axle nut is located on the right
side.
3.
4.
Loosen the rear wheel axle nut.
Loosen the lock nuts on each side. To
tighten chain turn chain puller adjusters
clockwise. To loosen chain turn adjus-
ters counterclockwise and push wheel
forward. Turn each adjuster exactly the
same amount to maintain correct axle
alignment. (There are marks on each
side of the rear arm and on each chain
puller; use them to check for proper
alignment.)
1. LO& nut
2. Adj”rter
3. Marks for align
4. near wheel axle nut
5. cotter pin
5.
6.
After adjusting, be sure to tighten the
lock nuts and the rear wheel axle nut.
Insert the cotter pin into the rear wheel
axle nut and bend the end of the cotter
pin (if the nut notch and the cotter pin
hole do not match, tighten the nut
1
slightly to match).
-CAUTION:
Excessive chain
tension will overload the
engine and other vital parts; keep the ten-
sion within the specified limits. Also,
replace the rear axle cotter pin with a new
one.
7. In the final step, adjust the play in the
brake pedal.
D. REAR BRAKE ADJUSTMENT
1.
a.
b
C
Pedal height
Loosen the adjuster lock nut (for pedal
height).
By turning the adjuster bolt clockwise
or counterclockwise, adjust the brake
pedal position so that its top end is
approx. 12 -
18 mm (0.47 - 0.71 in)
below the footrest top end.
Secure the adjuster lock nut.
-WARNING:
-
After adjusting the pedal height, the brake
pedal free play should be adjusted.
2. Free play
Turn the adjuster on the brake rod
clockwise or counterclockwise to pro-
vide the brake pedal end with a free play
of
20- 30 mm (0.79 - 1.18 in).
9

E. REAR BRAKE LINING INSPECTION
The specified thickness of the brake lining is 4
mm (0.16 in). The lining should be replaced
when it wears to less than 2 mm (0.079 in).
To check, see the wear indicator position
while depressing the brake pedal.

*ELECTRICAL ed that it can be started only when the trans-
mission is in Neutral or the clutch is disengag
ed.
STARTING CIRCUIT CUT-OFF SYSTEM
The starting circuit cut-off system is employ-
ed. Hence, the following description. Accordingly, the starter motor will not start
when the transmission is shifted into any
position other than neutral, unless the clutch
lever is pulled in
Description
This model is equipped with a starting circuit
cut-off switch. The starter motor is so
design-
COLOR CODE
Y Yellow
G Green
B Black
Br brown
Sb, B blue
R/W Red/White
B/Y Black,Yeliow
L/B Blue/Black
Function of the Diode in the Relay
When the transmission is in a position other
than Neutral:
Turning on the clutch lever switch (Clutch is
disengaged by pulling the clutch lever) makes
the safety relay to turn on.
In this case, the diode interrupts the flow of
current from the main switch to the neutral
indicator light and to the relay, and thus the
light will not come on.
Operation
a) When the transmission is in Neutral:
Neutral switch ON
Clutch lever switch OFF or ON
o When the main switch is turned on
while the transmission is in neutral the
starting circuit cut-off relay circuit is
closed and the relay is actuated.

2 When the “START” button is pressed,
the circuit from the main switch to
the relay
- starter switch assembly -
“START” (button) is closed, and the
starter switch assembly is turned on,
thus causing the starter motor to start.
b) When the clutch lever is released while
the transmission is in position other than
neutral:
Neutral switch OFF
Clutch lever switch OFF
- Since the starting circuit cut-off is
kept open, the relay is not actuated,
and it is impossible to turn on the
starter switch assembly by pushing the
“START” button.
As a result, the starter motor does not
run.
c) When the clutch lever is disengaged by
pulling in the clutch lever while the
transmission is in a position other than
neutral:
Neutral switch OFF
Clutch lever switch ON
Since the clutch lever switch is on while
the neutral switch is off, the following
circuit
- main switch - starting circuit
cut off relay - clutch lever switch is
closed and the relay is actuated.
The subsequent operation is the same as
a).
-lZ-

*SPECIFICATION
A. General
1. MODEL
1) Model (I.B.M. No.)
21 Basic color
‘XS650SH only **XS650H only
XS650SH (4M4/XS650H (4N9)
*CARDINAL RED or NEW YAMAHA BLACK
**BLACK GOLD
2. DIMENSION
1) Overall length
2) Overall width
3) Overall height
4) Seat height
5) Wheelbase
6) Minimum ground clearance
3. WEIGHT
1) Net weight (Dry)
4. PERFORMANCE
1) Climbing ability
2) Minimum turning radius
2.120 mm (83.5 ini
925 mm (36.4 in)
1,220 mm (48.0 in)
790 mm (31.1 ini
1,435 mm (56.5 ini
135 mm I 5.3 in)
“208 kg I459 lb)
“205 kg (452 lb)
26’
~ 2,500 mm 198.4 in/
B. Engine
L
1. DESCRIPTION
1) Engine type
2) Engine model
3) Displacement
4) Bore
x stroke
5) Compression ratio
6) Starting system
7) Ignition
System
8) Lubrication system
2. CYLINDER HEAD
1) Combustion chamber volume (with N-7Y)
Air cooled,
4.stroke. SOHC twin.
parallel forward incline
*4M4 **4N9
653 cc (39.85 cu.inl
75 x 74 mm (2.953 x 2.913 in)
8.7
: 1
Kick and electric starter
Battery ignition (Full transistor ignition)
wet sump
42.5 cc (2.59
win)
21 Combustion chamber type
3) Head gasket thickness
3. CYLINDER
1) Material
2) Bore size
3) Taper limit
4) Out of round limit
Dome +
Squish
1.2 mm IO.047 in)
Aluminum alloy with cast iron sleeve
75.00+~‘* mm i2.9528t~~oo8 in)
~ 0.05 mm (0.002 in)
~0.01 mm (0.0004 in)

4. PISTON
1) Piston skirt clearance
2) Piston oversize
3) Piston pin outside diameter x length
5. PISTON RING
1) Piston ring design
~0.050 - 0.055 mm 10.0020 - 0.0022 in)
75.25 mm ~ 15.50 mm 75.75 mm
76.00 mm
~2963 in, 12.972 I”/ (2.982 in, 12.5xX in, ,
20.0-:.005
mm x 61.0_;,3 mm
(0.79_&,2 in x 2.40&,,,, in)
2) Ring end gap
1.2mm (0.047 in, 1.5mm ,0.059 in, 2.*mm IO.110 inl
0.4 mm (0.008 - 0.016 in)
3) Ring groove side clearance (Top)
6. BIG END BEARING
11 Type
31 Bearing type
4) Cam dimensions
$25.$47-8
6) Camshaft deflection limit
7) Cam chain
Type
Number of links
Sprocket ratio
8. ROCKER ARM AND ROCKET SHAFT
i 0.03 mm (0.0012 in)
~ TSUBAKIMOTO BF05M
i 106L
~ 36/18 (2.000)
1) Rocker arm inner diameter
15.0+y8 mm (0.591+~oW7 in)
2) Rocker arm shaft diameter
15.07~:~~ mm (0.591~$~“,~ in)
3) Clearance 0.009
- 0.033 mm (0.00035- 0.00130 in1
4) Lift ratio X : Y = 40
: 48.41 mm (1.575 : 1.906 in)
l4-
Y

9. VALVE, VALVE SEAT AND VALVE GUIDE ~
1) Valve per cylinder
2) Valve clearance IIn cold engine)
3) Dimensions
Valve head diameter “A”
Valve face width “6”
Valve seat width “C”
Valve margin thickness “D”
Valve stem diameter
Valve guide diameter
Valve stem
to guide clearance
4) Valve face runout limit
0. VALVE SPRING
1) Free length
21 Spring rate
3) Installed length (Valve closed)
41 Installed pressure (Valve closed)
5) Compressed length (Valve open)
6) Compressed pressure (Valve open)
7) Wire diameter
8) Winding O.D.
91 Number of windings
2 pcs.
IN: 0.06 mm (0.0024 in)
EX: 0.15 mm (0.0059 in)
EX: 1.3 mm (0.051 in)
&
.4\----r
IN: 1.3 mm (0.051 in)
EX: 1.3 mm (0.051 in)
IN: 41 mm (1.614 in)
EX: 35 mm (1.378 in)
IN: 2.1 mm (0.083 in)
EX: 2.1 mm (0.083 in)
x B
IN: 1.3 mm (0.051 in)
$
D
IN: 8.0_g,o,5 mm (0.315_&,,0 in)
EX:8.0~~:~42~ mm 10.315I~:~~~ in)
IN: E.O:~:~~“, mm (0.315 :z:gi in)
EX: S.O:$~~~ mm (0.315 z:Ez in)
IN: O.OlO- 0.034 mm (0.00079- 0.00173 in)
EX: 0.035 - 0.059 mm 10.00138 - 0.00232 in)
IN & EX: 0.03 mm 10.0012 in) or less
INNER (IN/EX): 42 mm (1.654 in)
OUTER(IN/EX): 42.55 mm (1.675 in)
INNER (IN/EX): kl = 1.43 kg/mm 180.1 lb/in)
kz = 1.81 kg/mm 1101.4 lb/in)
OUTER(IN/EX): kl = 3.2 kg/mm (179.2 lb/in)
k2 = 4.18 kg/mm (234.1 lb/in)
INNER (INIEXI: 35 mm 11.378 in)
OUTER(IN/EX): 37 mm 11.457 in)
INNER (IN/EX): 10 f 0.7 kg (22.0 f 1.5 lb)
OUTER(IN/EX): 17.7 + 1.25 kg (39.0 f 2.8 lb)
INNER (IN/EX): 25.5 mm (1.004 in)
OUTER(IN/EX): 27.5 mm (1.083 in)
INNER (IN/EX): 27.2 f 1.9 kg (60.0 f 4.2 lb)
OUTERIIN/EX): 57.4 f4.0 kg (126.5 f 8.8 lb)
INNER (IN/EX): 2.9mm (0.114 in)
OUTER(IN/EX): 4.2 mm (0.165 in)
INNER (IN/EX): 19.4 mm (0.764 in)
OUTERIIN/EX): 32.6 mm (1.283 in)
INNER IINIEXI: 6.0 turns
OUTER(IN/EXI: 4.25 turns

I. CRANKSHAFT
1) Crankshaft deflection limit (A)
2) Con-rod large end clearance
(B)
31 Width of crankshaft
(Cl
(D)
41 Crank p,n I.D.
5, Crank piln O.D. x length
2. CONNECTING ROD
1) Big end I.D.
21 Small end I.D.
3. CRANK BEARING
1) Type Right end
Others
2) Oil seal fvpe
4. CLUTCH
1) Clutch type
2) Clutch operating mechanism
3) Primarv reduction ratio and method
4) Primary reduction gear back lash (4 teeth)
51 Friction plate
Thickness/Quantity
Wear limit
6) Clutch plate
ThicknerslQuantitv
Warp limit
7) Clutch spring
Free length/Quantity
8) Clutch housing radial plav
9) Push rod bending limit
5. TRANSMISSION
11 Tvoe
~ 0.05 mm (0.002 in)
0.15 - 0.4 mm (0.0059 - 0.0157 in)
66 -0.05 mm (2.598;$?,;; in)
-0.10
166_;.3 mm 17.323_;,o,2 in)
~ 26I;:;;j mm (1.024:;:;;; in)
26~&?06
x 65:;:; mm
34 +t016 mm ( 1.339+~.0006 in)
20$::85 mm 10.787:~:~o~ in)
~ 030.$78.:9 (Ball bearing)
032.068.17 (Rollar bearing)
SD-25-40-9
! Wet. multiple type
Inner push type. screw push sfstem
72/27 (2.6661, spar gear
~ 21.45_E,025 mm ~0.8445_~,o~,o in)
I
I 3 mm (0.118 in)/7 pcs.
2.7 mm (0.106 in)
1.4 mm (0.055
in)/6 PCS.
0.05 mm (0.002 in1
34.6 mm (1.362 in)/6 PCS.
0.027 - 0.081 mm (0.0011 - 0.0032 in)
~0.2 mm (0.008 in)
Constant mesh, 5-speed forward
-16-

c
t
L
2) Gear ratio: 1st 32113 (2.461)
2nd 27/l 7 (1.588)
3rd 26/20 (1.300)
4th
23/21 (1.095)
5th 22/23 (0.956)
31 Bearing: Main axle
(Left1
Needle bearing (@20-$30-20)
(Right1
Ball bearing ($25-e 52-20.6)
Drive axle (Left1 Ball bearing ($30.$62-23.61
(Right1
Needle bearing (020.030-161
41 Oil seal type Drive axle (Left) SDD-40-62-9
51 Secondary reduction ratio and method 34117
(Z.OOO)/Chain
16. SHIFTING MECHANISM
1 I Type
2) Oil seal type (Change lever)
17. KICK STARTER
1) Type
2) Oil seal type (Kick axle)
31 Kick clip friction tension
18. INTAKE
1) Air cleaner: Type/Quantity
2) Cleaner cleaning interval
19. CARBURETOR
1) Type and manufacturer/Quantity
T
L
_
i
21 I.D. mark
3) Main jet
4) Air jet
5) Jet needle
61 Needle jet
7) Throttle valve
8) Pilot jet
9l Pilot screw (Turns out)
101 starter jet
11 I Fuel level
12) Idling engine speed
20. LUBRICATION
1) Engine sump oil quantity
2) Oil type and grade
31 Oil pump type
4) Trochoid pump specifications
Top clearance
Tip clearance
Side clearance
Oil pump volume
5) Bypass valve setting pressure
(M.J.1
1A.J.l
(J.N.)
(N.J.)
(Th.V.)
(P.J.1
(P.S.1
IG.S.)
(F.L.)
Cam drum, return type
SDO-14-24-6
Bendix type
SD-25-35-7
1.2 - 1.7 kg (2.6 - 3.7 lb)
Dry. foam rubber/2 pcs.
Every 6,000 km (5,000 mile)
BS34 MIKUNl/2 pcs.
3G l-00
#132.5
#85
5HX12
Y-O
#135
#42.5
Preset
#30
27.3 + 0.5 mm (1.075? 0.020 in)
1.200 rlmin
Oil exchange: 2.0 lit (2.1 US qt)
Overhaul: 2.5 lit (2.6 US qt)
Yamalube
4-cycle oil or SAE 2OW/40 type
“SE” motor oil
Trochoid pump
0.10 - 0.18 mm (0.0039 - 0.0071 in)
0.03 - 0.09 mm (0.0012 - 0.0035 in)
0.03 - 0.08 mm (0.0012 - 0.0031 in)
1.3 litlmin (1.37 qtlminl at 1,000 rlmin
1.0 kg/cm’ (14 psi)
- 17-

6) Lubrication chart
- Pressure feed
- -- Splash lubrication
C. Chassis
1. FRAME
1) Frame design
2.
STEERfNG SYSTEM
1) caster
2) Trail
3) Number and size of balls in steering head
upper race
Lower
race
4) Steering lock to lock
3. FRONT SUSPENSION
1) Type
2) Damper type
3) Front fork spring
Free length
Wire diameter
x winding diameter
Spring constant
41 Front fork travel
51 Inner tube O.D.
6) Front fork oil quantity and type
Double cradle, high tensile frame
27O
115 mm (4.53 in)
19 pcs. l/4 in
19 pcs. l/4 in
42” each (L and R)
Telescopic fork
Oil damper, coil spring
482 mm
(18.99 in)
4 x 24.5 mm IO.157 x 0.965 in)
kl = 0.48 kg/mm 126.88 Iblinll
0 - 100 mm (0 - 3.94 in)
k2 = 0.65 kg/mm 136.40 lb/in)/
loo-
150 mm (3.94 - 5.91 in)
150 mm (5.906 in)
35 mm
(1.378 in)
169 cc (5.72 oz) each leg
Yamaha fork oil 1Owt or equivalent
Approx. 454 mm (17.9 in)
7) Distance from the top of inner tube oil level
without spring
4. REAR SUSPENSION
1) Type
2) Damper type
3) Shock absorber travel
Swing arm
Oil damper, coil spring
80 mm (3.15 in)