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 AgentFuels Containing Oxygenates
Gasoline frequently contains oxygenates
(alcohols and ethers) especially
in areas of the U.S. and Canada
which are required to sell such reformulated
fuels as part of a strategy to
reduce exhaust emissions.
The types and volume of fuel oxygenates
approved for use in unleaded
gasoline by th ...
Handlebar Removal
Remove:
Steering Damper (see Steering Damper Removal)
Clutch Lever Clamp Bolts [A]
Clutch Lever Assembly [B]
Left Switch Housing [C]
Handlebar Weight [D]
Left Handlebar Grip [E]
Remove:
Front Master Cylinder [A] (see Front Master Cylinder Removal
in the Brakes chapter)
...
Upper Fairing Assembly Disassembly
Remove:
Upper Fairing Assembly (see Upper Fairing Assembly
Removal)
Headlight (see Headlight Removal/Installation in the
Electrical System chapter)
City Light (LED) (see City Light (LED) Removal/Installation
in the Electrical System chapter)
Remove the screws [A], and separate each ...