SPECMAINTENANCE SPECIFICATIONS
2-8
Item Standard Limit
Ballancer
Ballancer drive method Gear
Clutch
Clutch release method Inner push, cam push
Friction plate thickness 2.72 - 2.88 mm •••
Wear limit ••• 2.60 mm
Plate quantity 6 pcs
Friction plate thickness 2.94 - 3.06 mm •••
Wear limit ••• 2.8 mm
Plate quantity 2 pcs
Clutch plate thickness 1.20 mm •••
Plate quantity 7 pcs
Max. warpage ••• 0.20 mm
Clutch spring free length 42.8 mm •••
Plate quantity 5 pcs
Clutch housing thrust clearance 0.070 - 0.071 mm •••
Transmission
Max. main axle runout ••• 0.08 mm
Max. drive axle runout ••• 0.08 mm
Shift mechanism type Cam drum and guide bar
Carburetor
ID mark 5CH5 10
Main jet #1:#150 #2:#145
Main air jet #1:1.0 #2:0.9
Jet needle #1:5C5A-3/5 #2:5Y18-3/5
Needle jet 2.600
Cutaway 4.00
Pilot air jet 1 # 0.8 mm
Pilot jet # 50
Bypass 1 # 1.0
Pilot screw turns out 2-3/4 +/- 1/2
Valve seat size 2.5
Starter jet 1 # 74
Float height 6.0 - 8.0 mm •••
Engine idle speed1,150-1,450 r/min •••
CO% 1.5 - 3 •••
Intake vacuum 30.6-33.36 kPa - 230-250 mm Hg •••
Lubrication systemDry sump
Oil filter type Paper type
Oil pump:
Oil pump type Trochoid type
Inner rotor to outer rotor tip clearance 0.12 mm 0.20 mm
Outer rotor to pump housing
clearance 0.030 - 0.080 mm 0.150 mm
Bypass valve opening pressure 80.0 - 120.0 kPa (0.8 - 1.2 kgf/cm
2) •••
Relief valve operating pressure 80.0 - 120.0 kPa (0.8 - 1.2 kgf/cm2) •••
Oil pressure (hot) 13.0 kPa (0.13 kgf/cm2)/1,300 r/min •••
Pressure check location Oil filter chamber •••
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2-20
SPECLUBRlCATlON POINTS AND LUBRICANT TYPE
LUBRlCATlON POINTS AND LUBRICANT TYPES
ENGINE
Lubrication points (part name) Lubricant type
Oil seal edges (completely)
Bearing retainer
Rod pins
Rod (big end)
Piston and piston rings
Hub (weight drive sprocket)
Piston pin
Valve stim and guide
Oil seal (valve stim end)
Rocker shaft and rocker arm
Cam and bearing (camshaft)
Rotor and rotor housing (oil pump)
Push rod (clutch)
Primary driven gear and main shaft
Sliding gear (transmission)
Idle gear (transmission)
Shift forks and bar
Shift cam and bearing (gearshift cam)
Shift shaft
Rod housing coupled surfaces Bonding agent (rapid seal adhesive)®
Yamaha bond No. 1215®
Coupled surfaces (cylinder head and cylinder head cover) Bonding agent (rapid seal adhesive)®
Yamaha bond No. 1215®
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SPECLUBRICATION LAYOUT
2-25
(1) Oil pump
(2) Oil filter
(3) Oil delivery hose
(4) Transmission
(5) Oil strainer[A] DELIVERY
[B] RETRIEVAL
A
B
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ENG
CHAPTER 5. ENGINE
ENGINE REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
MUFFLER, EXHAUST PIPE, ENGINE PROTECTOR, DRIVE SPROCKET,
CRANKCASE COVER, DRIVE SPROCKET AND SHIFT PEDAL . . . . . . . . . . . . . . . 5-1
ENGINE MOUNTING BOLT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
ENGINE DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
CYLINDER HEAD, CYLINDER, CAMSHAFT AND PISTON . . . . . . . . . . . . . . . . . . . . 5-5
INTERMEDIATE STARTER GEAR, CRANKCASE COVER (L)
AND GENERATOR STATOR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
CRANKCASE COVER (R), CLUTCH, PRIMARY DRIVE GEAR
AND BALANCER SHAFT GEAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9
OIL PUMP AND SHIFT LEVER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12
AC GENERATOR AND TIMING CHAIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13
CRANKCASE(R). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14
GEARBOX AND TRANSMISSION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
BALANCER SHAFT AND CRANKSHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17
OILSTRAINER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17
ROCKER ARMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18
VALVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
INSPECTION AND REPAIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21
CYLINDER HEAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21
VALVES AND VALVE GUIDES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
VALVESEAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23
VALVE SPRINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27
CAMSHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28
ROCKER ARMS AND ROCKER SHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28
CAMSHAFT CHAIN AND SPROCKET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29
CAMSHAFT CHAIN GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30
CYLINDER AND PISTON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30
PISTON RINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32
PISTONPIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-33
CLUTCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-33
OILPUMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-35
PRIMARY TRANSMISSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-35
TRANSMISSION AND GEARBOX. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-36
SHIFT SHAFT AND STOPPER LEVER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-37
STARTER TRANSMISSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-38
CRANKSHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-39
BALANCER SHAFT DRIVE
AND DRIVEN GEARS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-40
CRANKCASE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-40
BEARING AND OIL SEAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-40
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ENG
ENGINE ASSEMBLY AND SETTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-41
VALVES AND ROCKER ARMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-41
VALVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-42
ROCKER ARMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-43
CRANKSHAFT AND BALANCER SHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-44
TRANSMISSION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-46
GEARBOX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-47
TRANSMISSION AND GEARBOX. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-48
ENGINE OIL PUMP AND OIL STRAINER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-49
CRANKCASE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-50
ENGINE OIL STRAINER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-51
CRANKCASE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-51
SHIFT SHAFT AND OIL PUMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-52
TIMING CHAIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-54
PISTON AND RINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-55
CYLINDER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-56
CYLINDER HEAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-57
CAMSHAFT AND TIMING CHAIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-58
PISTON, CYLINDER, CYLINDER HEAD AND CAMSHAFT . . . . . . . . . . . . . . . . . . . 5-59
AC GENERATOR.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-65
OIL FILTER AND OIL HOSES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-67
BALANCER SHAFT GEAR AND PRIMARY
TRANSMISSION GEAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-68
CLUTCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-70
STARTER GEARS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-73
STARTER NEUTRAL GEAR AND CRANKCASE COVER (L) . . . . . . . . . . . . . . . . . 5-74
ENGINE REASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-76
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ENGINSPECTION AND REPAIR
5-35
7. Measure:
•Free length of clutch compression springs
(a)
Out of specification ➔Replace all springs.
OIL PUMP
1. Measure:
•Clearance between rotors (a)
(Between the internal rotor (1) and the
external rotor (2))
•Side clearance (b)
(Between the external rotor (2) and the
pump stator (3))
Out of specification ➔Replace oil pump.
Free length of clutch compression
spring (a): 42.8 mm
Oil pump clearances:
Clearance between 0.12 mm
rotors (a)
Side clearance (b) 0.03 ~ 0.08 mm
2. Inspect:
•Oil pump drive gear (1)
•Oil pump driven gear (2)
Wear/Cracks/Damage ➔Replace.
PRIMARY TRANSMISSION
1. Inspect:
•Primary drive gear teeth (1)
•Primary driven gear teeth (2)
Wear/Damage ➔Replace both gears.
Excess noise during functioning ➔
Replace both gears.
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ENGINE ASSEMBLY AND SETTING
5-46
ENG
TRANSMISSION
(1) Sprocket
(2) Oil seal
(3) Bearing
(4) Second wheel gear
(5) Secondary shaft
(6) Fifth wheel gear
(7) Third wheel gear
(8) Fourth wheel gear
(9) First wheel gear (10) Bearing
(11) Bearing
(12) Second sprocket gear
(13) Fifth sprocket gear
(14) Third sprocket gear
(15) Fourth sprocket gear
(16) Main shaft
(17) Bearing
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ENGENGINE ASSEMBLY AND SETTING
5-51
ENGINE OIL STRAINER
1. Install:
•Oil strainer (1)
•Oil passage cover (2)
Screw (oil strainer): 7 Nm (0.7 mkg)
Screw (oil passage cover): 7 Nm (0.7 mkg)
WARNING
Always use a new gasket.
Yamaha bond N° 1215 ®
:
P/N. 90890-85505
2 Install:
•Dowel pin (2)
3. Assemble the left crankcase to the right. Beat gently with a soft hammer.
NOTE:
Turn the shift cam as shown in the figure so that
it does not interfere with the crankcase during
assembly.
CRANKCASE
1. Apply:
•Yamaha bond N° 1215 ®
(1)
(on the crankcase mating surfaces)
Before installing and tightening the fastening
screws, be sure that the transmission is work-
ing properly by hand, turning the shift cam in
both directions.
CAUTION:
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