It is a 2 cycle engine and therefore you must use 2 cycle oil mixed at the correct ratio with the fuel.
Wee wee
that scooter takes 1 liter or 1.1 qt of sae 10w30
SAE 10w30 oil or Yamaha 4 Stroke Engine Oil
For a Yamaha Mio scooter, the transmission oil capacity is typically around 700ml. It is recommended to consult the owner's manual for the specific oil capacity and viscosity requirements for your scooter.
Yamaha's Yamalube, 2 stroke oil is a good choice.
sw 30
Yamaha's Yamalube, 2 stroke oil should work pretty good
Yamalube motor oil
Yamalube motor oil.
a good quality 2 stroke oil
Yamalube motor oil
2-Cycle Engine oil.