400 ex lubrication problems.

[Tommydp]

Here is my story, I bought a 400 ex in serious need of attention, I have now replaced the piston and rings, replaced the head with a used head, and replace the valve cover with a good used one, The problem i now have is this. The machine starts and runs like a champ, I am just not getting any oil on the cam chain side of the top end, it is causing a tap noise. I have since pulled the side cover and cleaned out any miscelaneous junk and gunk, still i am not getting oils to the top. I am preparing to change the plunger and spring under the cam now, does anyone know what would cause this? Any ideas on where I should be looking next?
thanks
Tommy:confused:

[Tommydp]

Also wanted to add, that i use only honda oil and the oil pump seems functional because it supplys the other side just fine. Any inside information on what im missing here would be appreciated! 'Thanks!

[m36indiana]

ck the screen on the bottom of the tank, it could be plugged up

[Tommydp]

Thanks to all who read this and the one who replied! I appreciate the input. Probably going to sell it or part it out as i cant sink any more money into this thing right now.