VALVE FACE WEAR
The thickness of the valve face decreases as the face wears.
Visually inspect each valve face for wear and replace any valve
with an abnormally worn face. Measure the valve face thickness
T. If it is out of specification, replace the valve with a new one.
% Valve head thickness (IN. & EX.):
Service Limit T: 0.5 mm
& 09900-20101: Vernier calipers
VALVE STEM RUNOUT
Support the valve using V-blocks, as shown, and measure its
runout with the dial gauge. If the runout exceeds the limit,
replace the valve.
% Valve stem runout (IN. & EX.):
Service Limit: 0.05 mm
& 09900-20701: Magnetic stand
09900-20607: Dial gauge (1/100 mm)
09900-21304: V-block (100 mm)
VALVE HEAD RADIAL RUNOUT
Place the dial gauge at right angles to the valve head, and mea-
sure the valve head radial runout.
If it measures more than limit, replace the valve.
% Valve head radial runout (IN. & EX.):
Service Limit: 0.03 mm
& 09900-20607: Dial gauge (1/100 mm)
09900-20701: Magnetic stand
09900-21304: V-block (100 mm)
#
Be careful not to damage the valve and valve stem
when handling it.
VALVE STEM DEFLECTION
Lift the valve about 10 mm from the valve seat. Measure the
valve stem deflection in two directions, "X" and "Y", perpendicu-
lar to each other, by positioning the dial gauge as shown. If the
deflection measured exceeds the limit, then determine whether
the valve or the guide should be replaced with a new one.
% Valve stem deflection:
Service Limit (IN. & EX.): 0.35 mm
& 09900-20607: Dial gauge (1/100 mm)
09900-20701: Magnetic stand
#
Be careful not to damage the valve and valve stem
when handling it.
ENGINE
3-28