Diagnostic Information And Procedures; Engine Mechanical Symptom Diagnosis; Compression Pressure Check - Suzuki kq750 Service Manual

Engine Mechanical Symptom Diagnosis

Refer to "Engine Symptom Diagnosis in Section 1A
(Page 1A-8)".

Compression Pressure Check

The compression pressure reading of a cylinder is a
good indicator of its internal condition.
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 seat. Refer to "Seat Removal and
Installation in Section 9D (Page 9D-11)".
3) Disconnect the fuel pump relay coupler (1).
1
4) Remove the spark plug. Refer to "Spark Plug Cap
and Spark Plug Removal and Installation in Section
1H (Page 1H-3)".

Diagnostic Information and Procedures

B831G21404001
B831G21404002
I831G1140003-01
5) Install the compression gauge and adaptor in the
spark plug hole. Make sure that the connection is
tight.
Special tool
(A): 09915–64512 (Compression gauge)
(B): 09915–63311 (Compression gauge
attachment)
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.
Compression pressure specification
Standard
Approx. 1 000 kPa
(10.0 kgf/cm
(Automatic decompression actuated)
Low compression pressure can indicate any of
the following conditions:
• Excessively worn cylinder wall
• Worn piston or piston rings
• Piston rings stuck in grooves
• Poor valve seating
• Ruptured or otherwise defective cylinder head
gasket
8) After checking the compression pressure, reinstall
the removed parts.
Engine Mechanical: 1D-2
(A)
(B)
I831G1140004-01
I831G1140005-01
2 , 142 psi)