Honda CRF1100A 2021 Owner's Manual page 252

Refuelling
Ignition key
Fuel fill cap
Do not fill with fuel above the level plate.
246
Fuel type: Unleaded petrol only
Lock cover
Fuel octane number: Your vehicle is
designed to use Research Octane Number
(RON) 91 or higher.
Fuel octane number: Your vehicle is
designed to use Research Octane Number
Level plate
(RON) 88 or higher.
Tank capacity:
18.8 L (4.97 US gal, 4.14 Imp gal)
24.8 L (6.55 US gal, 5.46 Imp gal)
#
II FO, III FO, II MA, III MA, KO, III KO type
III IN type
CRF1100A/AL/D/DL
CRF1100AL2/AL4/D2/DL2/D4/DL4
Refuelling and Fuel Guidelines
(P15)