Doing and oil change, and dropped the oil on the left side, and noticed that not much came out. Then dropped the oil on the right, and seemed to get most of the oil out. Didn't really think much of it. Filter looked clogged with black grit, and a little collapsed. I assumed that it was clutch. Plugged everything up, and put in 1L of oil. Checked dip stick, and there was no oil in at dip stick. Added 100ml of oil, no oil on dip stick. Checked oil filter, and oil in filter. Added 100ml of oil. Checked oil pressure screw, and found slow seep of oil. Checked dip stick, and oil just showed on stick. Dropped all the oil, and there was little on the left, and the rest on the right. Still very dirty. Pulled the oil tank breather, and can blow to the left side. Can't blow to the clutch side. How do you check oil passages, and oil flow?