Ive opend the throttle body because my scooter loose his power so i thought maybe i need to clean my throttle body but if you say its normal ... So ok..
What is the mileage on this scooter ?
Are you sure the engine oil level was not too high ? If the oil level was was too high and you were riding at high speed (high engine RPMS) maybe some oil ended up inside the Throttle Body.
You can also have good look at the spark plug comdition in future. If the engine oil level is correct and you ride at fairly low speed, the spark plug color should be fine and the throttle body should stay clean.
If the milage on the scooter is still low, there is a possibilty that the piston rings have not seated properly yet.
Or if the milage on the scooter is fairly high and you are worried, you can also do an engine compression test to compare with the manufacturer’s specifications.