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3. RELEASE AND INSTALLATION OF ENGINE
3-1 Starterd preparation data
＆
Simplified troubleshooting
※
Disassembling of Crankcase :
Before disassembling the crankcase, the engine must at first dismounted and the
following operations must be completed:
Air cleaner, carburettor, and air intake mounted
◎
.
Starter motor.
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Cylinder head cover, cylinder head.
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Cylinder, piston.
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Clutch cover, drive pully comp, driven pully comp.
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Rear wheel, rear shock absorber.
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Cooling fan, flywheel magneto.
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Oil pump.
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Standard preparation data for crank, cylinder, piston, and piston rings:
Unit: mm
125 c.c. Engine
151 c.c. Engine
Item
Checking part
Standard value
Allowable limit
Standard value
Allowable limit
Cylinder inner diameter
52.400-52.410 52.500 57.400-57.410 57.500
Roundness
-
0.05
-
0.05
Cylinder
Cylinder degree
-
0.05
-
0.05
Piston outer diameter
52.370-52.390 52.300 57.375-57.395 57.300
Inner diameter of piston pin
15.002-15.008 15.040 15.002-15.008 15.040
Gap between cylinder and piston
0.010-0.040 0.100 0.005-0.035 0.100
Top ring
0.015-0.055
0.090 0.015-0.050 0.090
Gap between
Piston and piston
ring
Second ring
0.015-0.055 0.090 0.015-0.050 0.090
Top ring
0.10-0.25
0.50
0.015-0.300
0.50
Second ring
0.10-0.25 0.50 0.015-0.300 0.50
Piston and
piston rings
Gap of piston ring
Lateral track of
oil scraper ring
0.2-0.7 - 0.2-0.9 -
Gap between piston and piston pin 0.002-0.014
0.020
0.002-0.014
0.020
Outer diameter of piston pin
14.994-15.000 14.960 14.994-15.000 14.960
Inner diameter of the hole at connecting rod
small end
15.016-15.034 15.060 15.016-15.034 15.060
Blow with compressed air the parts after cleaning and before measuring.
