Adjust the engine idle speed periodically on the engine at normal operating temperature.
To adjust the idle speed:

Engine oil and filter change
Throtile cable playCamshaft sprocket
Inspect the camshaft sprocket in the following
procedures:
remove the intake and exhaust camshafts. Refer to “engine top side
disassembly” .
Inspect the teeth of each camshaft sprocket for wear
or damage.
If they are worn or damaged, replace the sprocket/
camshaft assembl ...
Engine assembly installation
Install the engine in the reverse order of engine removal.
Pay attention to the following points:
before installing the engine, install the collars (1).
Before installing the engine, install the engine
mounting thrust adjusters (2).
Gradually raise the rear side of ...
Oil pressure regulator / oil strainer
inspection
Refer to “oil pan / oil pressure regulator / oil strainer removal and
installation” .
Oil pressure regulator
Inspect the operation of the oil pressure regulator by
pushing the piston with a proper bar.
If the piston does not operate smoothly, replace the oil
pressure regulator with a new on ...