KTM 125 DUKE 2021 Owner's Manual page 240

24 SUBSTANCES
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Fuel with an ethanol content of up to 10% (E10 fuel) is safe to use.
238
Info
Do not use fuel containing methanol (e.g., M15, M85, M100) or more than 10% ethanol (e.g., E15,
E25, E85, E100).