oil blowing out of muffler

Hi ; I have a 1982 Kz 1000 ltd barn find .I rebuilt most of the engine . Had  to get another head as the fellow cranked the cam holder bolts to tight and pulled the treads out and when he tried to fix it made a total mess off it. cleaned the head up put in new valve seals . had the barrels honed new rings . Put it all together  and it ran like a charm . Except the left muffler was splewing smoke and oiled up the side of the tire  took it for a boot ran like a scared rabbit . Did fowl #2 plug lots of oil . OIl also leaked out of th muffler for a bit when off . so thought it was the Exhaust valve seal  so replaced that Same thing . so took it apart again  seen oil in #2 carb close to engine  Replaced Both exhaust and intake  valve seals  checked rings . Put all back together start and runs well  but still smoking Seams not as bad But still there Only took it out for maybe 8 miles  maybe whats left in muffler  not sure . Anyway to the Question has any one have this problem before, Also have another 1982 1000 ltd that is my daily ride Well as soon as the weather gets nice Thanks for reading my novel
Al

Did you make sure the oil ring expander spring isn't overlapping?

Yup when i rechecked the rings i made sure they were in the proper position relative to each other . so i took a close look . with oil in outlet of carb starting to think there might be a crack in the head i can't see

Sorry to be redundant but this is what I'm referring to.  It's quite common for the expander spring to overlap instead of butting the ends like shown.
 

Great picture of that item Nessism!

Rick H.

!00% for sure {maybe] i got that . but when i take it apart again i will look very careful at that . By the way that is a great picture ...    Al

Well tore it apart again  rings are fine when i put the new ones in one end is blue the other red so easy to see if there is a over lap guide for the valves seem ok too.  will have to take a real close look at the head , when i took the carbs off the intake . there was lots of oil in the carb on #2 cylinder

Could the valve guide on that intake valve have come loose or somehow developed a crack? Could it be badly worn?

seems ok but i'm going to take a really close look tomorrow at it . let you know

took it right down to the barrels no wear right tol same with pistons and rings [ to the best of my abilities any  way. tested the valve guides seam good thought i would check the valves them self. On #2 intake just before seal there was a gouge 0.010 deep so that when it was pushed in it was in the seal. not sure if  the seal spring could  cover this  but keeping my fingers crossed this is it . not sure how i damaged the valve stem must of  been while installing it so no more working in low light and when tired
 

Well still blowing oil out of #2 changed and checked piston for size.  cylinder walls in tol . changed valve and seal. next tear down will probably change guide , the oil that leaks back in carb is quite a bit . #2 fired for about 10 seconds than became fouled so i think piston problem or it's at the intake can not see any cracks but dosn't mean there not there. one more try then it's a parts bike
 

Do you have a crankcase breather hose attached to the airbox?