cant see through sight glass

alright so i put oil in it but i was looking at the sight glass and didnt see anything so i eventually filled up the whole crankcase with oil. drained it out and put about 650 to 700 ml in there and then i went to put it in gear and clutch had no effect it shifted jumped and stalled. so i drained it again and i made sure i put 650ml in it and it is still doing it. what happened to it