Suzuki 2005 GSF1200 Service Manual page 70

1D-2 Engine Mechanical:
Compression Pressure Check
The compression pressure reading of a cylinder is a
good indicator of its internal condition.
The decision to overhaul the cylinder is often based on
the results of a compression test. Periodic maintenance
records kept at your dealership should include
compression readings for each maintenance service.
NOTE
• Before checking the engine for
compression pressure, make sure that the
cylinder head nuts are tightened to the
specified torque values and the valves are
properly adjusted.
• Make sure that the battery is in fully-
charged condition.
1) Warm up the engine.
2) Remove the fuel tank. Refer to "Fuel Tank Removal
and Installation: in Section 1G".
3) Remove all of the spark plugs.
4) Remove the frame head cover, left and right.
(GSF1200) Refer to "Exterior Parts Removal and
Installation: in Section 9D".
5) Install the compression gauge and adaptor in one of
the spark plug holes. Make sure that the connection
is tight.
Special tool
(A): 09915–64510 (Compression gauge set)
(B): 09915–63210 (Compression gauge
adaptor)
(B)
Diagnostic Information and Procedures
B649G11404001
(A)
I649G1140310-01
6) Keep the throttle grip in the fully-opened position.
7) Press the starter button and crank the engine for a
few seconds. Record the maximum gauge reading
as the cylinder compression.
8) Repeat this procedure with the other cylinders.
Compression pressure specification
Standard
1 250 kPa 875 kPa
(12.5 kgf/cm 2 , (8.75 kgf/cm
178 psi) 124 psi)
Low compression pressure can indicate any of
the following conditions:
• Excessively worn cylinder walls
• Worn piston or piston rings
• Piston rings stuck in grooves
• Poor valve seating
• Ruptured or otherwise defective cylinder head
gasket
Overhaul the engine in the following cases:
• Compression pressure in one of the cylinders is
less than 875 kPa (8.75 kgf/cm
• The difference in compression pressure between
any two cylinders is more than 200 kPa (2 kgf/
cm 2 , 124 psi)
• All compression pressure readings are below 1
000 kPa (10 kgf/cm
measure more than 875 kPa (8.75 kgf/cm
psi)
9) After checking the compression pressure, reinstall
the removed parts.
I649G1140311-01
Limit Difference
200 kPa
2 , (2 kgf/cm 2
psi)
2 , 124 psi)
2 , 142 psi) even when they
2 , 124
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