DAELIM VJF125 Service Manual - page 145
10-7
CYLINDER HEAD / VALVES
Reface the valve seats and clean the cylinder head
thoroughly to remove any metal particles.
Support the cylinder head and drive the old guides out
of the combustion chamber side of the cylinder head.
TOOL : VALVE GUIDE DRIVER
Apply oil to a new O-ring and install it onto a new
valve guide.
Drive the new guide in from the camshaft side of the
cylinder head while the cylinder head is still heated.
TOOL : VALVE GUIDE DRIVER
When reaming new valve guides, insert the valve
guide reamer from the combustion chamber side.
TOOL : VALVE GUIDE REAMER
Using a torch to heat the cylinder head may cause
warping.
Wear insulated gloves to avoid burns when handling
the heated cylinder head.
Avoid damaging the head when driving the valve
guide out.
Take care not to tilt or lean the reamer in the guide
while reaming.
Otherwise, the valve is installed slanted, that causes
oil leaks from the stem seal and improper valve seat
contact and results in the valve seat refacing not able
to be performed.
Use cutting oil on the reamer during this operation.
Rotate the reamer clockwise, never counterclockwise
when inserting and removing.
VALVE SEATS INSPECTION / REFACE
Clean all intake and exhaust valves thoroughly to
remove carbon deposits.
Apply a light coating of Prussian Blue to each valve
face.
Tap the valve against the valve seat serveral times with
the valve guide reamer, without rotating the valve, to
check for proper valve seat contact.
Remove the valve and inspect the valve seat face.
The valve seat contact should be within the specified
width and evenly all around the circumference.
If the valve seat width is not within specification,
reface the valve seat.