Honda EU30i Manual page 160

CYLINDER HEAD/VALVES
INSPECTION
CYLINDER COMPRESSION CHECK
Warm the engine to normal operating temperature.
Turn the engine switch knob to the OFF position, and
then remove the drain screw to drain the carburetor.
Remove the spark plug cap from the spark plug.
Remove the spark plug using a spark plug wrench.
Pull the recoil starter several times to expel unburned
gas.
Attach a commercially available compression gauge (1)
to the spark plug hole.
Pull the recoil starter forcefully until the gauge reading
stops rising.
CYLINDER COMPRESSION:
0.42 MPa (4.3 kgf/cm
CYLINDER HEAD WARPAGE
Remove the carbon deposits from the combustion
chamber (page 14-3).
Clear off any gasket material from the cylinder head
surface.
Check the spark plug hole and valve areas for cracks.
Check the cylinder head warpage using a straight edge
(1) and feeler gauge (2).
SERVICE LIMIT:
If the measurement is more than the service limit,
replace the cylinder head.
VALVE SEAT WIDTH
Thoroughly clean the combustion chamber and valve
seats to remove carbon deposits.
Inspect each valve face for irregularities.
If necessary, replace the valve (page 14-4).
Apply a light coat of Prussian Blue or erasable felt-
tipped marker ink to the each valve seat.
Insert the valve, and snap it using a valve lapper (1)
closed against its seat several times. Be sure the valve
does not rotate on the seat. The transferred marking
compound will show any area of the valve face that is
not concentric.
Measure the valve seat width of the cylinder head.
STANDARD:
SERVICE LIMIT:
If the measurement is more than the service limit,
recondition the valve seat (page 14-9).
Check whether the valve seat contact area of the valve
is too high.
If the valve seat is too high or too low, recondition the
valve seat (page 14-9).
2 -1
, 61 psi) /600 min (rpm)
0.10 mm (0.004 in)
0.7 – 0.9 mm (0.03 – 0.04 in)
2.0 mm (0.08 in)
CYLINDER HEAD
(1)
(2)
(1)
(1)
14-5