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Compression Check: Testing and Inspection





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.
2 Fully open the throttle.
3 While cranking the engine, measure the compression pressure.

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.
Compression pressure: 1,400 kPa (14.3 kgf/cm2, 203 psi)
Minimum pressure: 1,000 kPa (10.3 kgf/cm2, 145 psi)
Difference between each cylinder: 110 kPa (1.1 kgf/cm2, 16 psi)

4 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.
- 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 leak age past the gasket.