2-18 PERIODIC MAINTENANCE
Periodic Maintenance Procedures
Engine Top End
Air Suction System Damage Inspection
Disconnect the air switching valve hose [A] out of the right
air cleaner housing.
Start the engine and run it at idle speed.
Plug the air switching valve hose end with your finger and
feel vacuum pulsing in the hose.
If there is no vacuum pulsation, check the hose line for
If there is no leak, check the air switching valve (see Air
Switching Valve Unit Test in the Electrical System chap-
ter) or air suction valve (see Air Suction Valve Inspection
in the Engine Top End chapter).
Valve Clearance Inspection
Valve clearance must be checked and adjusted when
the engine is cold (room temperature).
Cylinder Head Cover (see Cylinder Head Cover Re-
moval in the Engine Top End chapter)
Timing Inspection Plate (Engine Left Side)
Set the front piston at TDC (see Camshaft Installation in
the Engine Top End chapter).
Using a thickness gauge [A], measure the valve clearance
between the rocker arm [B] and the shim [C].
Set the rear piston at TDC by turning the crankshaft coun-
terclockwise 305° (see Camshaft Installation in the En-
gine Top End chapter).
Using a thickness gauge, measure the valve clearance
between the rocker arm and the shim.
Exhaust 0.20 ∼ 0.25 mm (0.0079 ∼ 0.0098 in.)
0.10 ∼ 0.15 mm (0.0039 ∼ 0.0059 in.)
If the valve clearance is not within the specified range,
first record the clearance, and then adjust it.