ZHEJIANG KAYO MOTOR CO., LTD.
Scratches on the piston or cylinder wall
3
Engine overheated
Excessive carbon deposits in the piston
4
Knocking or abnormal noise
Pistons or cylinders are worn
Excessive carbon deposits in the piston
REMOVAL OF CYLINDER BLOCK The cylinder block removal steps are as follows:
1. Remove the cylinder head.
2. Remove the fastened chain guide roller pin and aluminum pad Φ8.
3. Take out the chain guide roller, and remove the M6×23 cross-slot bolt connecting the cylinder block and the
crankcase body.
4. Remove the cylinder block, cylinder block gasket, and O-ring seal.
Note
：
1. If the cylinder block gasket is damaged, scrape the remaining gaskets on the cylinder surface and the
crankcase joint surface with a scraper. Then replace with a new gasket to prevent engine oil leakage after
reassembly.
2. If the paper pad is immersed in gasoline, it is easy to disassemble. When doing this work, avoid
damaging the cylinder contact surface.
The removed parts must be properly placed to avoid damage and loss.
CYLINDER BLOCK INSPECTION
The inspection steps of the cylinder are as follows:
1. Check whether the cylinder is worn or damaged.
2. Measure the inner diameter of the cylinder, take three positions, namely the top, middle and bottom of the
piston stroke, and measure the two directions at right angles to each other during the measurement.
Repair limit value
：
φ47.018mm
。
REMOVAL OF PISTON AND PISTON RING
The steps for removing the piston and piston ring are as
follows:
1. Use needle-nose pliers to remove the piston pin retaining ring.
2. Remove the piston pin.
3. Remove the piston.
4.
Remove the piston ring.
NOTE
: Do not drop the retaining ring into the crankcase.
PISTON AND PISTON RING INSPECTION
The inspection steps for pistons and piston rings are as follows:
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