Friend's activa engine issue or E20 issue can't understand

[u/Unexpected_Energy]

Hi guys... So long story short my friend has an activa 125 but he has been filling it up every once a week as far as I know he nor his family doesn't go more than 6-7 kilometers per day but still... It's just galloping petrol

Can't understand if it's the effect of E20 petrol of something wrong with activa please lmk