Engine Compression: Compression

Check engine compression at normal operating temperature at specified cranking speed. Release fuel pressure. See FUEL SYSTEM . Remove left air duct and disconnect power transistor connectors. Remove left harness connector bracket and ornamental rocker covers. Disconnect harness connector between ignition coil and power transistor. Remove ignition coil bracket and bracket with ignition coils. Remove all spark plugs. Depress accelerator pedal fully to hold throttle valve wide open. See COMPRESSION SPECIFICATIONS table.

NOTE: If cylinder compression in one or more cylinders is low, repeat inspection using a small amount of oil poured into each cylinder. If compression pressure increases, piston rings may be worn or damaged. If compression pressure does not increase, a valve may be sticking or seating improperly. If compression in any 2 adjacent cylinders is low and does not change after oil is added, there is a leak past head gasket. Make repairs as needed and reinspect.

COMPRESSION SPECIFICATIONS ⁽¹⁾

Application

psi (kg/cm² )

Standard

185 (13.0)

Minimum

142 (10.0)

Maximum Variation Between Cylinders

14 (1.0)

⁽¹⁾	Readings taken at cranking speed (300 RPM).