Slide out the rubber cap [A].

Starter Motor InstallationCompression Damping Force Adjustment
There are two adjustments you can make to the compression
damping force.
High Speed Compression Damping Adjuster [A]
Low Speed Compression Damping Adjuster [B]
To adjust the high speed compression damping force, turn
the outside damping adjuster with a wrench to the desired
position ...
Oil Pressure Relief Valve Inspection
Remove the oil pressure relief valve (see Oil Pressure
Relief Valve Removal).
Check to see if the valve [A] slides smoothly when pushing
it in with a wooden or other soft rod, and see if it comes
back to its seat by spring [B] pressure.
NOTE
Inspect the valve in its assembled stat ...
Shift Fork Guide Pin/Drum Groove Wear Inspection
Measure the diameter of each shift fork guide pin [A], and
measure the width [B] of each shift drum groove.
If the guide pin on any shift fork is less than the service
limit, the fork must be replaced.
Shift Fork Guide Pin Diameter
Standard: 6.9 7.0 mm (0.272
0.276 in.)
Service Limit: ...