'61HN252' by American Honda Motor Co. - Page 168 of 540
http://services.honda.com/ServiceManual/SVC_MNL/61HN253/61HN2...
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3/9/2008 10:49 PM
[2005-2008] [TRX500 FA/FGA]
CYLINDER HEAD/VALVE/CAMSHAFT
CYLINDER COMPRESSION
Warm up the engine to normal operating tempera-
COMPRESSION GAUGE
ture.
Stop the engine, disconnect the spark plug cap and
remove the spark plug
(page 3-9).
Install the compression gauge into the spark plug
hole.
Shift the transmission in neutral.
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:
608 902 kPa (6.2 9.2 kgf/cm
2
, 88 131 psi) at 450
rpm (min
-1
)
Check that there is no leakage at the gauge connec-
tion.
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
CYLINDER HEAD COVER REMOVAL/
DISASSEMBLY
REMOVAL
Remove the fuel tank
(page 5-21).
THROTTLE CABLE
HEAT
Release the radiator upper hose, SE valve cable and
GUARD
SE VALVE CABLE
throttle cable.
Remove the fuel tank heat guard.
Remove the wire clamp from the fuel tank heat
guard.
WIRE CLAMP
RADIATOR UPPER HOSE
Remove the four bolts and valve adjusting hole
caps.
BOLTS
VALVE ADJUSTING HOLE CAP
8-6