RE: 4 cycle lubrication
Hi
valves should not leak, they should seat properly. I would check the valve lash to ensure you have the correct gap! It could be that too little gap is keeping the valve from seating properly.
This could also be the reason the engine is running roughly for you as you will also be losing compression. Set them up correctly now and then recheck after run-in.
As far as lubrication goes, some oil gets to the crankcase via piston ring blowby and lubricates the bottom end/cam gear /valve gear. Its a good idea to prelube these areas prior to breakin as it will probably not have any lube there from new. Most manuals tell you to do this prelube as a lot of wear will take place till oil finds its waycompletely through the engine.
Let us know how it runs after adjustment.
Regards
Steve