Ok guys still new to motorbikes, but need some help with oil levels.
Toke the bike out for lunch, and as i do looked at the oil window, and and it was about 3/4 full (towards the top) on the way out to lunch it didn't sound right so i stoped checked the bike over and have alook at the oil window, and it's now empty

So my question is should you be able to see oil in the window when the bike is running, and how do i check the oil level? (ie. i know my car states to have running then with 10sec of turning off, check oil level) Does anyone know the procedecure for checking oil levels in the zzr250.
Thanks in advanced