PGO ALLORO 125, Service Manual

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A.Troubleshooting.
If the cylinder head is malfunctioned, usually it can tell from the measurement of the
Compression pressure or from the noise that comes from the upper part of the engine.
1.Unsmooth idle speed
-
Compression pressure is too low.
2.Insufficient compression pressure. 5.Abnormal noise
-Poor adjustment of valve clearance -Poor adjustment of valve clearance
-Valve being burned out or bent -Valve burned or damaged spring
-Valve timing is not correct -Camshaft is worn out.
-Valve spring is damaged. –Chain adjuster is worn out.
-Poor sealing of valve base. –Camshaft, valve rocker arm is worn out.
-Leakage in Cylinder head gasket.
-Cylinder head twisted or cracked.
-Spark plug is not properly installed.
3.Compression pressure is too high.
-
There is too much carbon accumulated in the combustion chamber.
4.There is white fume coming out from the exhaust pipe.
-The valve stem or valve guide pipe is worn out.
-Valve stem’s oil seal is damaged.
B.The operation data information
Description
IN/EX
Standard Value
(mm)
Limit of use
(mm)
IN 0.08
－
Clearance between adjuster tapped
Screw and valve stem
(Before warm up)
EX 0.08
－
Compression pressure(throttle open
full)
11kg/650rpm (150CC)
IN 26.625(150CC) 26.23(150CC)
Height of the cam’s convex part
EX 26.53(150CC) 26.13(150CC)
IN 10.00~10.015 10.10
Inner diameter of rocker arm shaft
EX 10.00~10.015 10.10
IN 9.972~9.987 9.91
Outer diameter of rocker arm shaft
EX 9.972~9.987 9.91
Valve base angle
IN&EX 1.0 1.8
IN 4.975~4.900 4.90
Outer diameter of valve stem
EX 4.955~4.970 4.90
IN 5.000~5.012 5.30
Inner diameter of valve guide
EX 5.000~5.012 5.30
IN 0.010~0.037 0.08
Clearance between valve stem and
Valve guide
EX 0.030~0.057 0.10