Compression Pressure Check - Suzuki GSX1200 1999 Service Manual

COMPRESSION PRESSURE CHECK

The compression 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 mainte-
nance records kept at your dealership should include compression readings for each maintenance service.
COMPRESSION PRESSURE SPECIFICATION
Standard
1 250 kPa
2
(12.5 kgf/cm
)
Low compression pressure can indicate any of the following conditions:
* Excessively worn cylinder wall
* Worn-down piston or piston rings
* Piston rings stuck in grooves
* Poor seating of valves
* 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
* Difference in compression pressure between any two cylinders is more than 200 kPa (2 kgf/cm
* All compression pressure are below 1 000 kPa (10 kgf/cm
(8.75 kgf/cm ).
2
COMPRESSION TEST PROCEDURE
NOTE:
* Before testing the engine for compression pressure, make sure that the cylinder head bolts are tightened to
the specified torque values and valves are properly adjusted.
* Have the engine warmed up by idling before testing.
* Be sure that the battery used is in fully-charged condition.
Remove the parts concerned and test the compression pressure
in the following manner.
• Remove the seat and fuel tank. ($4-3)
• Remove all the spark plugs.
• Fit the compression gauge in one of the plug holes, while taking
care that the connection tight.
• Keep the throttle grip in full-open position.
• While cranking the engine a few seconds with the starter, and
record the maximum gauge reading as the compression of that
cylinder.
• Repeat this procedure with the other cylinders.
& & & & 09915-64510: Compression gauge &
09915-63210: Adaptor
Limit
875 kPa
2
(8.75 kgf/cm
)
Difference
200 kPa
2
( 2 kgf/cm
)
) even when they measure more than 875 kPa
2
PERIODIC MAINTENANCE 2-21
).
2
).
2