If they appear damaged or deteriorated, replace them.

Balancer Adjustment
Torque LimiterThermostat Removal
Remove:
Fuel Tank (see Fuel Tank Removal in the Fuel System
(DFI) chapter)
Air Cleaner Housing (see Air Cleaner Housing Removal
in the Fuel System (DFI) chapter)
Throttle Body Assy (see Throttle Body Assy Removal in
the Fuel System (DFI) chapter)
Throttle Body Assy Holder Clamp [A]
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Seat Cutter Operation Care
1. This valve seat cutter is developed to grind the valve for
repair. Therefore the cutter must not be used for other
purposes than seat repair.
2. Do not drop or shock the valve seat cutter, or the diamond
particles may fall off.
3. Do not fail to apply engine oil to the valve seat cutter
...
Exploded View
AL: Tighten the two clamp bolts alternately two times to ensure even
tightening torque.
G: Apply grease.
R: Replacement Parts
G: Apply grease.
L: Apply a non-permanent locking agent.
R: Replacement Parts
Specifications
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