2009 Suzuki 400 LTZ Quad Sport Service Manual, Page 144Get this manual
Engine Mechanical: 9) Press the starter button and crank the engine for few secondsRecord the maximum gauge reading as the cylinder compressionCompression pressure specification Standard Approx1 100 kPa (11.0 kgfcm2, 156 psi) (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 10) After checking the compression pressure, reinstall the removed parts