Hardening, shrinkage, or damage of both gaskets and O-rings after disassembly can reduce sealing performance.
Remove old gaskets and clean the sealing surfaces thoroughly so that no gasket material or other material remains.
Install the new gaskets and replace the used O-rings when re-assembling.

Force
Liquid Gasket, Non-permanent Locking AgentOxygen Sensor Installation (Equipped Models)
NOTICE
Never drop the oxygen sensor [A] especially on a
hard surface. Such a shock to the unit can damage
it. Do not touch the sensing part [B] to prevent oil
contact. Oil contamination from hands can reduce
sensor performance.
Tighten:
Torque - Oxygen Sensor: 25 N·m (2.5 kgf·m, 18 ...
Valve Seat Repair
Repair the valve seat with the valve seat cutters [A].
Special Tools - Valve Seat Cutter Holder Bar [B]: 57001
-1128
Valve Seat Cutter Holder, 4.5 [C]: 57001
-1330
[For Exhaust Valve Seat]
Valve Seat Cutter, 45° - 27.5:
57001-1114
Valve Seat Cutter, 32° - 28:
57001-1119
Valve Seat ...
Oil Pump Drive Gear Installation
Install is the reverse of removal. Note the following.
First, engage the oil pump chain [A] to the gears, and then
install the oil pump drive gear [B].
Turn the “OUT” mark [C] to outside.
Apply a non-permanent locking agent to the oil pump drive
chain guide bolt and the oil pump drive ...