Piston Disassembly/Assembly; Cylinder/Piston Inspection - Honda GX690 Workshop Manual

CYLINDER

PISTON DISASSEMBLY/ASSEMBLY

Remove the piston (page 14-2).
PISTON RING SET
ASSEMBLY:
The top ring (1) and second ring (2) are not
interchangeable.
Install the top ring and second ring on the piston
with the mark side facing up.
Check that the piston rings rotate smoothly after
installing them.
Space the piston ring end gaps 120 degrees
apart, and do not align the ring end gaps with the
piston pin bore.

CYLINDER/PISTON INSPECTION

CYLINDER COMPRESSION CHECK
Start the engine and warm up to normal operating
temperature.
Turn the fuel valve lever of the application to the OFF
position, and then loosen the carburetor drain screw to
drain the float chamber.
Remove the spark plug cap from the spark plug.
Remove the spark plug using a spark plug wrench.
Operate the starter motor to expel unburned gas.
Attach a compression gauge (1) to the spark plug hole.
Operate the starter motor to measure stable cylinder
compression.
Do not operate the starter motor for more than 5
seconds at a time. When operating the starter motor
several times in a row, wait 10 – 20 seconds between
operation to recover the battery voltage.
CYLINDER COMPRESSION:
0.5 – 0.7 MPa (5.09 – 7.14 kgf/cm
min -1 (rpm)
14-6
MARK
120°
120°
10 mm (0.4 in)
(1)
(2)
2 , 73 – 102 psi) / 500
TOP RING
SECOND RING
120°
SIDE RAIL
SPACER
10 mm (0.4 in)
(1)
OIL RING
(COMBINATION
RING)