ZHEJIANG KAYO MOTOR CO., LTD.
Check whether the rocker arm shaft is worn out, if the wear is serious, you need to replace it with a new rocker arm
shaft.
Inspection of camshaft parts
The camshaft convex hull has no obvious unevenness when touched by handThe inspection steps of camshaft parts
are as follows:
1. Check whether the camshaft peach tip and base circle are worn out, and whether the camshaft bearing rotates
flexibly. If the camshaft is worn out or the bearing is spinning, it should be replaced with a new camshaft
component.
Check whether there are cracks in the pressure reducing valve slinger combination, the spring does not rebound,
and whether the pressure reducing valve centrifugal slinger and the mandrel are loose. If so, the pressure reducing
valve slinger combination needs to be replaced.
CYLINDER HEAD INSPECTION
The inspection steps of the cylinder head are as follows:
1. Check whether the sealing of the cylinder head is good. If the sealing of the cylinder head is poor, replace the
cylinder head or valve with a new one.
2. Check the spark plug hole and valve seat for cracks.
3. Check whether the cylinder head is deformed, and use a knife-edge ruler and feeler gauge to check the flatness
of the cylinder head.
Check whether the oil baffle is damaged.
INSPECTION AND GRINDING OF THE
VALVE SEAT Check and grind
steps of the valve seat are as follows:
Remove the carbon deposits in the combustion chamber completely, apply a thin layer of red ink evenly on the
valve seat, place the valve on the valve seat and knock the valve lightly without rotating it, and then pull out the
valve if it touches the working surface of the valve. If the trace is discontinuous, the valve seat should be polished
and repaired.
When grinding, first remove the carbon deposits on the intake and exhaust valve seats, and then apply
abrasives and then use a rubber-head grinding tool to suck up the valves and grind the valve seats.
CHECK THE
VALVE GUIDE
Use a dial indicator to measure the inner diameter of each valve catheter and make a record.
Repair limit value
：
φ5.035 mm
Note: Before measuring the inner diameter of the valve guide, the carbon deposits in the guide should be
completely removed.
If the valve guide needs to be replaced, the valve seat should be polished again, and each valve should be inserted
into the guide, observe its movement, and finally calculate the gap between the valve stem and the valve guide.
Valve clearance maintenance limit value
：
1. Intake valve
：
0.07 mm
；
Exhaust valve
：
0.08mm.
REPLACEMENT OF THE VALVE GUIDE
Put the
cylinder head in a thermostat and heat it to 100
～
150 degrees Celsius, take out and support the cylinder head
(be careful not to burn), and remove it with a valve. Install the tool to drive the valve guide toward the side of
the rocker chamber
2. Press-fit the new valve guide and ream the newly installed valve guide after the cylinder head cools down.
1. Clean the cylinder head with cleaning agent, and use compressed air to remove the metal chips on the cylinder
head.
Note: When removing the valve guide, do not damage the cylinder head.
Note: When reaming, the reamer must be coated with cutting oil, and the reamer should be rotated when
loading or unloading.
MEASURE THE VALVE SEAT-AREA
1.
WIDTH
Measure the width of the valve seat contact surface. Repair limit value: 1.5 mm
2. If the valve seat is too wide, too narrow or has dents, you should grind the valve seat to achieve the correct
degree of sealing.
3. When grinding the valve, use an electric holster to cover the rubber tube (with a tight fit), then cover the valve
stem on the rubber tube, apply a little graphite paste for grinding to the valve sealing tape, and then fit it on the
valve seat sealing line , start the stun gun, rotate the valve, and grind the valve and the seat ring.
After grinding, check whether the sealing line between the valve and the seat ring has been ground out, otherwise it
should be re-ground. If the grinding is not in place, replace the valve or cylinder head.
Assembly the cylinder
head
1.
Install the oil baffle cover on the valve guide.
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