Honda WT20X Owner's Manual page 13

2. Check the fuel level.
Use automotive unleaded gasoline with a Research Octane Number of
91 or higher (a Pump Octane Number of 86 or higher).
Never use stale or contaminated gasoline or an oil/gasoline mixture.
Avoid getting dirt or water in the fuel tank.
Gasoline is extremely flammable and is explosive under certain
conditions.
Refuel in a well-ventilated area with the engine stopped. Do not
smoke or allow flames or sparks in the refueling area or where
gasoline is stored.
Be careful not to spill fuel when refueling. Spilled fuel or fuel vapor
may ignite. If any fuel is spilled, make sure the area is dry before
starting the engine.
Avoid repeated or prolonged contact with skin or breathing of
vapor.
KEEP OUT OF REACH OF CHILDREN.
Gasoline substitutes are not recommended; they may be harmful to
the fuel system components.
With the engine stopped and on a level surface, remove the fuel tank
cap and check the fuel level.
Refill the tank if the fuel level is low.
Do not fill the fuel tank completely. Fill tank to approximately 25 mm (1
inch) below the top of the fuel tank to allow for fuel expansion. If may
be necessary to lower the fuel level depending on operating
conditions.
After refueling, make sure the tank cap is closed properly and securely.
MAXIMUM FUEL LEVEL
12
FUEL TANK TOP
(strainer type)
MAXIMUM FUEL LEVEL
(non-strainer type)
25 mm
(1 inch)