While doing an engine oil change to winter weight oil (.....found only one 5W50 oil as recommended by owner's manual and the bottle stated it was "the perfect oil for vintage autos." ?? So, bought the 5W40 Synthetic. Ideas/opinions here, anyone?))
...today, I removed the fill bolt for the gear oil and went fishing in the hole for the oil level with a piece of soft wire, bent in an "L" shape. I recently drained the gear oil and refilled, per the manual, with 180ml of oil. I did find the level of the oil and it was about 3/8ths of an inch below the fill hole. This is with the scoot on the center stand.
So, this indicates to me that I should keep measuring 180ml of gear oil into the scoot when I do gear oil changes.
It would be easier to just fill until it weeps out of the fill hole - but apparently this would be filling the scoot with more oil than is recommended by KYMCO.