Compression Pressure Check; Compression Test Procedure - Suzuki TU250X Service Manual

2-24 PERIODIC MAINTENANCE

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 mainte-
nance records kept at your dealership should include compression readings for each maintenance service.
COMPRESSION PRESSURE SPECIFICATION
Standard
1 200 – 1 400 kPa
(12 – 14 kgf/cm 2 , 171 – 199 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
NOTE:
When the compression pressure goes below specification, check the engine for conditions listed above.

COMPRESSION TEST PROCEDURE

NOTE:
* Before testing 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.
* Warm up the engine before testing.
* Make sure that the battery is fully-charged.
Remove the related parts and test the compression pressure in
the following manner:
• Remove the front seat. (8-3)
• Lift up the fuel tank by removing the fuel tank mounting bolt.
(5-3)
• Remove the spark plug. (2-7)
• Install the compression gauge and adaptor in the spark plug
hole. Make sure that the connection is tight.
• Keep the throttle grip in the fully opened position.
• Press the starter button and crank the engine for a few sec-
onds.
• Record the maximum gauge reading as the cylinder compres-
sion.
 09915-63210: Compression gauge adaptor
09915-64512: Compression gauge
Limit
850 kPa
(8.5 kgf/cm 2 , 121 psi)