Compression Check: Testing and Inspection
INSPECTION1. INSPECT COMPRESSION
(a) Warm up and stop engine.
(b) Remove ignition coil.
(c) Remove spark plugs.
(d) Inspect cylinder compression pressure.
SST: 09992-00500
(1) Insert a compression gauge into the spark plug hole (Procedure "A").
(2) Fully open the throttle (Procedure "B").
(3) While cranking the engine, measure the compression pressure (Procedure "C").
Compression pressure:
1,300 kPa (13.3 kgf/cm2, 189 psi)
Minimum pressure:
1,000 kPa (10.2 kgf/cm2, 145 psi)
Difference between each cylinder:
100 kPa (1.0 kgf/cm2, 15 psi)
NOTICE:
- Always use a fully charged battery to obtain engine speed of 250 rpm or more.
- Check other cylinder's compression pressure in the same way.
- This measurement must be done in as short a time as possible.
(4) If the cylinder compression in one or more cylinders is low, pour a small amount of engine oil into the cylinder through the spark plug hole and repeat procedure "A" through "C" for cylinders with low compression.
HINT:
- If adding oil helps the compression, it is likely that the piston rings and/or cylinder bore are worn or damaged.
- If pressure stays low, a valve may be sticking or seating is improper, or there may be leakage from the gasket.