2009 Suzuki 400 LTZ Quad Sport Service Manual, Page 143Get this manual
1D-1 Engine Mechanical:
Engine Mechanical
Diagnostic Information and Procedures
Engine Mechanical Symptom Diagnosis
5) Disconnect the fuel pump lead wire coupler (1)Refer to "Engine Symptom Diagnosis in Section 1A (Page 1A-7)"B933H21404001
Compression Pressure Check
The compression pressure reading of cylinder is good indicator of its internal conditionThe decision to overhaul the cylinder is often based on the results of compression testPeriodic maintenance records kept at your dealership should include compression readings for each maintenance serviceNOTE 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 fullycharged condition1) Warm up the engine2) Remove the fuel tank lower coverRefer to "Fuel Tank Removal and Installation in Section 1G (Page 1G-9)"3) Remove the spark plugRefer to "Spark Plug Cap and Spark Plug Removal and Installation in Section 1H (Page 1H-4)"4) Install the compression gauge and adaptor in the spark plug holeMake sure that the connection is tightSpecial tool (A): 0991564512 (Compression gauge) (B): 0991563311 (Compression gauge attachment)