DAELIM NS125DLX Service Manual page 90

Cylinder Head/Valve
● Remove the valve spring, valve cotter, retainer,
spring and valve.
Tool: Valve spring compressor
NOTE
•To prevent the loss of tension, do not compress
the valve spring more than necessary.
NOTE
•Mark the disassembled parts so that they can be
reassembled into the original position later.
● Remove the valve spring seat and valve stem
seal. Remove carbon deposits from the inside of
the combustion chamber.
Cylinder Head
● Remove gasket marks from the cylinder head
gasket.
NOTE
•Take precautions not to damage the cylinder
head gasket attachment.
● Check the spark plug assembling hole and the
valve seat for cracks.
● Using a square and a feeler gauge, check the
cylinder head distortion.
Service limit: 0.1mm(0.004in)
Valve Spring
● Measure the free length of the valve spring.
Service limit: 36.90mm(1.4528in)
NOTE
•Replace the valve spring with new one if the
length of any one is less than the service limit.
Clearance Between Valve Steam and Guide
● Check the valve for bend, seizure, or damage, and
check the stem for abnormal wear.
● Insert the valve into the valve guide, and check
the operation.
● Measure, and record, the outer diameter of the
valve stem.
Service limit: I N: 4.920mm(0.1937in)
EX: 4.900mm(0.1929in)
9-6
Valve spring compressor