Compression Check: Testing and Inspection
INSPECT COMPRESSION
Warm up and stop engine.
Remove ignition coil.
Remove spark plugs.
Inspect cylinder compression pressure.
SST 09992-00500
Insert a compression gauge into the spark plug hole.
Fully open the throttle.
While cranking the engine, measure the compression pressure.
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.
If the cylinder compression in one more cylinders is low, pour a small amount of engine oil into the cylinder through the spark plug hole and repeat steps (1) through (3) 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.