Cylinder Compression; Cylinder Head Cover Removal/ Disassembly - Honda 2005 FOURTRAX FOREMAN TRX500 TM Service Manual

CYLINDER HEAD/VALVE
CYLINDER COMPRESSION
The cylinder
compression
specification is
comparatively low
because the
camshaft has a
decompression
device installed.
Warm up the engine to normal operating
temperature.
Stop the engine and remove the spark plug
(page 4-9).
Install the compression gauge into the spark plug
hole.
Shift the transmission in neutral and close the choke
knob (OFF).
Open the throttle all the way and crank the engine
with the starter motor until the gauge reading stops
rising. The maximum reading is usually reached
within 4 - 7 seconds.
COMPRESSION PRESSURE:
440 kPa (4.5 kgf/cm
2
, 64 psi) at 380 rpm (min
1
)
Check that there is no leakage at the gauge
connection.
Low compression can be caused by:
- blown cylinder head gasket
- improper valve adjustment
- valve leakage
- worn piston ring or cylinder
High compression can be caused by:
- carbon deposits in combustion chamber or on
piston head
COMPRESSION GAUGE
CYLINDER HEAD COVER REMOVAL/
DISASSEMBLY
REMOVAL
Remove the fuel tank and heat guard plate
(page 6-22).
Set the piston position to Top Dead Center on the
compression stroke (page 4-10).
If you plan to remove the rocker arms, loosen the
rocker arm shaft retaining bolts.
Remove the following:
- nine bolts
- head cover
SHAFT RETAINING BOLTS
8-7