Motorcycle Repair: 2004 honda 400ex (atv), 2004 honda 400ex, oil tank

Question
I'm having a problem with my 2004 honda 400ex. It starting making a metal to metal noise I first thought rings, then timing chain. I've lost no power, and not smoking. Kinda think it's the oil pump. Just one of those feelings. do have any suggestions how i should trace this problem down or narrow my search. Theres a hose coming from the oil tank to top of the head cap, I started my atv then carefully removed this hose and got no oil. Figured I should have gotten covered, not sure of direction of oil flow, but surly I should have gotten something. Can you give me some direction?

Answer
you most definitely should have been sprayed by oil, figure this... oil has to travel down the head into all the spots requiring lube... you were on the right track and did exactly what I would have. Your oil pump is bad, replace this part and I believe you will have no trouble, be sure to double check all the oil lines and channels before and after exchanging the pump, debris can be a nasty thing.