If they appear damaged or deteriorated, replace them.

Balancer Adjustment
Torque LimiterCrankshaft Side Clearance Inspection
Insert a thickness gauge [A] between the thrust washer
[B] on the crankcase and the crank web [C] at the #3 main
journal to determine clearance.
If the clearance exceeds the service limit, replace the
thrust washers as a set and check the width of the crankshaft
#3 main journal.
Cra ...
Tachometer
The tachometer shows the engine
speed in revolutions per minute (r/min,
rpm).
On the right side of the tachometer
face is a portion called the “red zone”.
Engine r/min (rpm) in the red zone is
above maximum recommended engine
speed and is also above the range for
good performance.
...
Air Suction System Damage Inspection
Separate the air switching valve hose [A] from the lower
air cleaner housing [B] (see Air Cleaner Housing Removal
in the Fuel System (DFI) chapter).
Connect the following parts temporarily.
Fuel Pump Lead Connector [A]
Extension Tube [B]
Air Cleaner Housing (see Air Cleaner Hou ...