Page 25 of 382
SPECMAINTENANCE SPECIFICATIONS
2-4
MAINTENANCE SPECIFICATIONS
ENGINE
Item Standard Limit
Cylinder head
Max. warpage ••• 0.03 mm
Cylinder
Bore 94.970 - 95.020 mm 95.10 mm
Measuring point 50 mm •••
Camshaft
Drive system Chain drive (left)
Camshaft cap inside diameter 23.000 - 23.021 mm •••
Camshaft journal diameter 22.967 - 22.980 mm •••
Camshaft-journal-to-camshaft-cap
clearance 0.020 - 0.054 mm •••
Camshaft lobe dimensions:
Intake-measurement A 36.470 - 36.570 mm •••
Intake-measurement B 30.060 - 30.160 mm •••
Intake-measurement C 6.41 mm •••
Exhaust-measurement A 36.620 - 36.720 mm •••
Exhaust-measurement B 30.110 - 30.210 mm •••
Exhaust-measurement C 6.51 mm •••
Max. camshaft runout ••• 0.030 mm
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Page 26 of 382

SPECMAINTENANCE SPECIFICATIONS
2-5
Item Standard Limit
Timing chain
Model/number of links 75-010/126
Tensioning system Automatic
Rocker arm/rocker arm shaft
Arm inside diameter 12.000 - 12.018 mm •••
Shaft outside diameter 11.976 - 11.991 mm •••
Arm-to-shaft clearance 0.009 - 0.042 mm •••
Valve, valve seat, valve guide
Valve clearance (cold) intake 0.05 - 0.10 mm •••
exhaust 0.12 - 0.17 mm •••
Valve dimensions:
Valve head diameter A intake 36.90 - 37.10 mm •••
exhaust 31.90 - 32.10 mm •••
Valve face width B intake 2.260 mm •••
exhaust 2.260 mm •••
Valve seat width C intake 1.00 - 1.20 mm 1.80 mm
exhaust 1.00 - 1.20 mm 1.80 mm
Valve margin thickness D intake 1.00 - 1.40 mm 0.80 mm
exhaust 0.80 - 1.20 mm 0.65 mm
Valve stem diameter intake 6.975 - 6.990 mm 6.995 mm
exhaust 6.955 - 6.970 mm 6.925 mm
Valve guide inside
diameter intake 7.000 - 7.012 mm 7.042 mm
exhaust 7.000 - 7.012 mm 7.042 mm
Valve stem to valve
guide clearance intake 0.010 - 0.037 mm 0.08 mm
exhaust 0.030 - 0.057 mm 0.10 mm
Valve stem runout ••• 0.010 mm
Valve seat width intake1.10 mm 1.80 mm
exhaust 1.10 mm 1.80 mm
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Page 27 of 382

SPECMAINTENANCE SPECIFICATIONS
2-6
Item Standard Limit
Valve spring
Inner spring:
Free length intake40.10 mm 38.10 mm
exhaust 40.10 mm 38.10 mm
Installed length
(valve closed) intake22.70 mm •••
exhaust 22.70 mm •••
Compressed spring force
(installed)intake164.80 - 190.20 N •••
16.80 - 19.39 kg •••
exhaust 164.80 - 190.20 N •••
16.80 - 19.39 kg •••
Spring tilt intakeintake •••2.5 °/1.7 mm
exhaust ••• 2.5 °/1.7 mm
Winding direction
(top view)intakeClockwise
exhaust Clockwise
Outer spring:
Free length intakeintake43.80 mm 38.10 mm
exhaust 43.80 mm 38.10 mm
Installed length
(valve closed)intake34.20 mm •••
exhaust 34.20 mm •••
Compressed spring force intake71.60 - 87.30 N •••
(installed)7.3 - 8,9 kg •••
exhaust 149.10 - 182.40 N •••
15.2 - 18.6 kg •••
Spring tilt intake •••2.5 °/1.7 mm
exhaust ••• 2.5 °/1.9 mm
Winding direction
(top view)intakeCounterclockwise
exhaust Counterclockwise
Piston
Piston-to-cylinder clearance 0.045 - 0.065 mm 0.15 mm
Diameter D 94.915 - 94.965 mm •••
Height H 5.0 mm •••
Piston pin bore inside diameter 22.004 - 22.015 mm •••
Offset 2.00 mm •••
Offset direction Intake side
Piston pin outside diameter 21.991 - 22.000 mm •••
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Page 28 of 382
SPECMAINTENANCE SPECIFICATIONS
2-7
Item Standard Limit
Piston ring
Top ring:
Ring type Barrel
Dimensions (B x T) 1.20 x 3.80 mm •••
End gap
(installed) 0.30 - 0.45 mm 0.70 mm
Ring side clearance 0.040 - 0.080 mm 0.130 mm
2
ndring:
Ring type Plain
Dimensions (B x T) 1.20 x 3.80 mm •••
End gap
(installed) 0.30 - 0.45 mm 0.80 mm
Ring side clearance 0.030 - 0.070 mm 0.130 mm
Oil ring:
Dimensions (B x T) 2.50 x 3.40 mm •••
End gap
(installed) 0.20 - 0.70 mm •••
Ring side clearance 0.020 - 0.060 mm •••
Crankshaft
Width A 74.95 - 75.00 mm •••
Max. runout C ••• 0.030 mm
Big end side clearance D 0.350 - 0.650 mm •••
Big end radial clearance 0.010 - 0.025 mm •••
Small end free play F 0.80 mm •••
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Page 29 of 382

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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Page 30 of 382
2-9
SPECMAINTENANCE SPECIFICATIONS
Cylinder head tightening steps:
Crankcase tightening steps:
Right crankcase Left crankcase
ENGINE
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Page 31 of 382

SPECMAINTENANCE SPECIFICATIONS
2-10
Tightening
Part torque
Part to be tightened
nameThread size Remarks
Nm mkg
Cylinder head Washer
based bol M8 x 1.25 29 2.9
Cylinder head Stud bolt M10 x 1.25 20 2.0
Cylinder head Hexagon socket
head screw M6 x 1.0 10 1.0
Cylinder head Stud bolt M6 x 1.0 7 0.7
Cylinder head:
Cap (oil check) Union bolt M6 x 1.0 7 0.7
Spark plug – M12 x 1.25 18 1.8
Cylinder head cover Hexagon socket
head screw M6 x 1.0 10 1.0
Tappet cover (intake) Hexagon socket
head screw M6 x 1.0 10 1.0
Tappet cover (exhaust) – M32 x 1.5 12 1.2
Cylinder Crown nut M8 x 1.25 22 2.2
Cylinder Nut M10 x 1.25 42 4.2
Cylinder Hexagon socket
head screw M6 x 1.0 10 1.0
Weight drive gear Hexagon nut M16 x 1.0 60 6.0
Rotor (A.C. magneto) Hexagon nut M14 x 1.5 120 12.0
Lock nut (valve adjusting screw) Hexagon nut M6 x 1.0 14 1.4
Cam chain sprocket Washer based
bolt M7 x 1.0 20 2.0
Cam chain stopper guide Hexagon socket
head screw M6 x 1.0 10 1.0
Cam chain stopper guide Washer based
screw M16 x 1.0 20 2.0
Rocker shaft Hexagon socket
head screw M6 x 1.0 10 1.0
Oil pump Hexagon socket
head screw M6 x 1.0 10 1.0
Oil delivery/retrieval pipe Pan screw M6 x 1.0 7 0.7
Oil draining pipe Washer based
screw M14 x 1.5 30 3.0
Oil filter cover Hexagon socket
head screw M6 x 1.0 10 1.0
Bleed screw (oil filter cover) Hexagon screw M5 x 0.8 5 0.5
Push lever (clutch) Pan screw M8 x 1.0 12 1.2
Push rod (clutch) Hexagon nut M6 x 1.0 8 0.8
Sprocket Hexagon nut M18 x 1.0 115 11.5
Lock washer (oil seal) Hexagon screw M6 x 1.0 10 1.0
Stop lever Bolt M6 x 1.0 10 1.0
Shift cam Hexagon screw M6 x 1.0 10 1.0
Stator Pan head (+)
screw M5 x 0.8 5 0.5
Tightening torques
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Page 32 of 382

SPECMAINTENANCE SPECIFICATIONS
2-11
Tightening
Part torque
Part to be tightened
nameThread size Remarks
Nm mkg
Stator (pick-up coil) Hexagon socket
head screw M6 x 1.0 7 0.7
Engine oil pipe 1 Hexagon socket
head screw M6 x 1.0 10 1.0
Engine oil pipe 2 Union screw M12 x 1.25 35 3.5
Oil delivery pipe Union bolt M8 x 1.25 18 1.8
Carburetor joints Hexagon socket
head screw M6 x 1.0 10 1.0
Air filter case (frame) Hexagon screw M6 x 1.0 10 1.0
Air filter case (frame) Washer based
screw M6 x 1.0 10 1.0
Exhaust pipe Washer based
nut M6 x 1.0 10 1.0
Exhaust pipe protector Pan head (+)
screw M6 x 1.0 7 0.7
Muffler Hexagon socket
head screw M8 x 1.25 23 2.3
Muffler (band) Nut, nylon M8 x 1.25 23 2.3
Muffler Washer based
screw M8 x 1.25 23 2.3
Crankcase Hexagon socket
head screw M6 x 1.0 10 1.0
Crankcase Stud bolt M10 x 1.25 20 2.0
Crankcase cover (right) Hexagon socket
head screw M6 x 1.0 10 1.0
Crankcase cover (left) Hexagon socket
head screw M6 x 1.0 10 1.0
Sprocket cover Hexagon socket
head screw M6 x 1.0 10 1.0
Stop washer (bearing) Flat headscrew M6 x 1.0 7 0.7
Pressure plate Washer based
screw M6 x 1.0 8 0.8
Clutch housing Hexagon nut M20 x 1.0 90 9.0
Primary drive gear Hexagon nut M20 x 1.0 120 12.0
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