When the engine is running, the air intake valve is lifting up.
If the valve does not operate properly, check the air intake solenoid valve hoses for leak.
If there are no leaks, check the air intake solenoid valve.

Air Intake Solenoid Valve Unit TestCoupling Bearing Inspection
Since the coupling bearing is made to extremely close
tolerances, the clearance can not normally be measured.
NOTE
It is not necessary to remove the coupling bearing for
inspection. If the bearing is removed, it will need to be
replaced with a new one.
Turn the bearing in the coupling b ...
Crankshaft Installation
NOTE
If the crankshaft is replaced with a new one, refer to
the Connecting Rod Big End Bearing/Crankshaft Main
Bearing Insert Selection in the Specifications.
NOTICE
If the crankshaft, bearing inserts, or crankcase
halves are replaced with new ones, select the bearing
inserts and check cleara ...
Special Tools and Sealant
Oil Pressure Gauge, 10 kgf/cm²:
57001-164
Oil Pressure Gauge Adapter, PT3/8:
57001-1233
Outside Circlip Pliers:
57001-144
Liquid Gasket, TB1211:
56019-120
...