Cylinder Compression Measurement
Use the battery which is fully charged.
Warm up the engine thoroughly.
Stop the engine.
Fuel Tank (see Fuel Tank Removal in the Fuel System
Air Cleaner Housing (see Air Cleaner Housing Removal
in the Fuel System (DFI) chapter)
Stick Coils (see Stick Coil (Ignition Coil together with
Spark Plug Cap) Removal in the Electrical System chap-
Spark Plugs (see Spark Plug Removal in the Electrical
Attach the compression gauge [A] and adapter [B] firmly
into the spark plug hole.
Using the starter motor, turn the engine over with the throt-
tle fully open until the compression gauge stops rising; the
compression is the highest reading obtainable.
Special Tools - Compression Gauge, 20 kgf/cm
Compression Gauge Adapter, M10 × 1.0 [B]:
Usable Range: 980 ∼ 1 498 kPa (10.0 ∼ 15.3 kgf/cm
142 ∼ 217 psi) at 240 r/min (rpm)
Repeat the measurement for the other cylinders.
Install the spark plugs.
Torque - Spark Plugs: 13 N·m (1.3 kgf·m, 113 in·lb)
The following table should be consulted if the obtainable compression reading is not within the us-
Carbon accumulation on piston and in
combustion chamber possibly due to
is higher than
damaged valve stem oil seal and/or
damaged piston oil rings (This may be
indicated by white exhaust smoke).
Incorrect cylinder head gasket thickness
Gas leakage around cylinder head
is lower than
Bad condition of valve seating
Incorrect valve clearance
Incorrect piston/cylinder clearance
Bad condition of piston ring and/or piston
ENGINE TOP END 5-23
Remove the carbon deposits and
replace damaged parts if necessary.
Replace the gasket with a standard part.
Replace damaged check gasket and
cylinder head warp.
Repair if necessary.
Adjust the valve clearance.
Replace the piston and/or cylinder.
Inspect the cylinder and replace/repair
the cylinder and/or piston as necessary.
Replace the piston and/or the piston