Smoking from breather and exhaust during high rpm

Hello. I have a 1979 kz1000e1 st that Ive been rebuilding.. just when i think im about there, I notice another issue . I just replaced the valve cover gaskett and half moons and checked the valves while I was in there.. everything was peachy... however, after the bike warms up the breather filter (i have a pod setup)smokes. Also, when idling and i rev it hard to like 7000+rpm its smokes pretty good out of the exhaust... but it doesnt smoke while riding or at any other time... or at least I havent noticed it. The smoke is white and smells of bruning oil. I checked oil level and its fine, but i tried adding more oil and then drained oil to be less than where i had it originally, just to make sure oil level wasnt the issue. Its of course wasnt that simple. just cleaned and synced carbs, fresh fuel, fresh oil, fresh fuel and oil filters... I cant think of any other stupid small things i can hope it would be. Before I start crying about having to do a full topend rebuild, does anyone have any other suggestions?

A lot of info in your post but not much was helpful. You said you were quote rebuilding unquote a 79 shafty but then said you were contemplating a top end rebuild. What have you done to the engine? If you basically haven't done anything, the most likely source of this smoke is the valve stem oil seals. The oil seals allow some oil to ride the valves for lubrication but not enough oil is supposed to get through to cause oil to get into the combustion chambers. The oil seals are rubber caps that are about as big as the tip of your pinky finger. These things tend to get harden and deform when they get old and more oil will get by than should. The other alternative is the rings are not sealing. To figure out what might be needed, do a compression test. Your shafty should get about 125-145 PSI per cylinder. If it is getting less, the rings may be the issue. To check the rings, pour one teaspoon of oil into #1 plug hole and recheck the compression. If you had only gotten 90 PSI, it will shoot up to 150 PSI or so with the OIL sealing the ring/bore gap. Do the teaspoon of oil test for each cylinder. If you find that your compression is pretty good and uniform, then the valve stem oil seals are the culprit and your description makes me think this might be the issue. In the event you suspect this is the problem, the fix is relatively easy. You take off the cylinder head, disassemble the valve train, decarbon the combustion chambers and lap in the valves and install new valve stem oil seals. The only special tool needed is a valve spring compressor. I have done this job MANY times and it only takes a few hours. I would do it anyway if going though an older bike.

i suppose the term rebuilding caused some confusion... nothing has been done to the engine, its everything else so far that ive gone through. other than checking valve clearance and resealing the valve cover w/ a new gaskett and half moons the engine is still original to my knowledge. Looks like your thoughts are along the same lines as mine...

It sounds like you have worn rings. The worn rings are allowing combustion gas to pass by the rings and lighting up the oil on the pistons and causing smoke out the breather. The opposite pistons on the crank will cause smokey oil to again bypass the rings into the combustion chamber and be expelled out the exhaust. Worn valve seals will compound the problem. Sounds like you need a ring and valve job.....chris4

compression on the second cylinder starting from the left is low... its at ~100 while the others range from ~125-145 and none of them were identical, so i do beelive its the rings as you say. I just had the valves themselves checked and i was told they were all in good tolerance... In any case, how big of a job is it to replace the rings? how much would this cost at a shop? is there a walkthrough anywhere so i can see if im up for the job? im a mechanical engineering student, and am fairly mechanically inclined but have never really delved this far into an engine before, but there is a first time for everything i suppose... if someone would be kind enough to tell me the parts I need and what id need to do, that would be great... my roomie has a manual for an 81 kz1100 laying around, and i would assume its fairly similar to my bike, but if its an easy enough job, i would probably purchase the proper service manual.

The kz1100 manual will give u a good idea of what is involved, they are very similar. You will definitely need the correct manual to do the job though.
u did not report all the compression test readings (with and without oil). If u did not do this, I would reread George’s very informative post and do as he advice. This will tell us more about the condition of the valves and rings. Then u will be able to get the best advice possible.