Rocker box leaking oil

My 1975 KZ400 rocker box is leaking oil pretty bad, especially after it is ridden for 15 or 20 minutes at higher speeds. I think it is my rocker shaft arm o-rings that need to be replaced. Any suggestions on size of O-rings, or how to do this? If any one has done this or has any suggestions how to I would greatly appreciate it.

I am also wondering if it is possible to do this without pulling the engine apart and only pulling the rocker shaft out a little to replace the o-rings.

If you're talking about the o-rings labeled "3" in the diagram below, they are still an "Active" Kawasaki part, so any local or online dealer can get them for you. Partzilla lists them at $4.35 each. I suggest you consult the Kawasaki Service Manual for the replacement procedure. You may find the procedure in the second link below. Ed

find.partzilla.com/?r=t&q=92055-098&x=4&y=7
www.kz400.com/WorkshopManFrameset-5.html

Rocker box no longer leaking oil!
This was very easy to do with out removing the cylinder head. just make sure the pistons are at top dead center so you can with the rocker arm shaft out enough to get the the o-rings and put it back in.

Only problem now is I have a ticking noise with the bike it running. I did not have the piston at top dead center when I was first trying to pull rocker arm shaft out, could this have messed up with rocker arm? and that it where the ticking is now coming from? if so, how big of a deal is that, can i still run the bike if the noise doesnt bother me?

Other question, now my valves need some adjusting, I tried adjusting them after i out the rocker arms back in but now my bike is a little harder to start (battery is bad so I only use kickstart). does any one know what could be going on or how I could adjust the valves better?