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 AgentCylinder (Upper Crankcase) Wear Inspection
Split the crankcase (see Crankcase Splitting).
Remove the pistons (see Piston Removal).
Assemble the cylinder (upper crankcase) [A], the cylinder
head [B] and the cylinder head gasket [C].
Tighten the cylinder head bolts (see Cylinder Head Installation
in the Engine Top End chapter).
...
Engine Removal
Support the rear part of the swingarm with a stand.
Squeeze the brake lever slowly and hold it with a band
[A].
WARNINGMotorcycle may fall over unexpectedly
resulting in
an accident or injury. Be sure to hold the front brake
when removing the engine.
NOTICE
Be sure ...
Water Temperature Sensor Resistance Inspection
Refer to the Water Temperature Sensor Inspection in the
Electrical System chapter.
If the reading is within the standard, but the problem still
exists, replace the ECU (see ECU Removal/Installation in
the Fuel System (DFI) chapter).
Water Temperature Sensor Circuit
1. ECU
2. Water T ...