Smoke on start up, suggestions?

Just trying to figure out why my 79 KZ1000 ltd smokes every now and then when I start up. With the old head, about 1 in every 10 times I would start it it would smoke on left pipe (4 into 2 stock exhaust) for about 10 to 15 mins, then clear up and no more smoke. I figured the valve seals were old and tired so I replaced the head. I had another head for it that I cleaned up, lapped valves, new seals etc and put on bike. Was a low mileage head and the guides are in great condition. Compression is great. Is it possible I got some bad seals? I am thinking because the bike sits at an angle on the kickstand that oil pools at that end which would explain the left side smoking only.
Any thoughts?

If you are sure the new head is set up right, it sounds like maybe a flaky oil ring? Maybe a leak down test could catch it. I kind of doubt a new seal was bad, but it's possible. If the symptoms are the same, points to a different cause.

Sure sounds like intake valve seal(s) again . Pull the plugs if one looks slightly blackish now you have found the suspect cylinder.

xxsierraxx wrote: I am thinking because the bike sits at an angle on the kickstand that oil pools at that end which would explain the left side smoking only.
Any thoughts?

I don't think it collects that way. The oil pools in each "lifter pocket" in the head under each cam lobe so each one has a full load of oil in it. It will leak at whatever seal it can.

On mine, when the seals go bad, I see burned oil on the spark plugs.

I just went and checked plugs and they are all good except #2. It is fouled. I started the bike, it smoked a bit and when it warmed up and was at idle I removed the plug boots one at a time. All but #2 made a difference. Kept running with #2 plug off, when I reconnected it was sputtery and a slight miss. The reason I did head change to begin with was after a leak down test I discovered keak in head gasket at#2. Was coming out at head bolt. So new head went in, gaskets etc.
Would bad rings or weak compression pull alot of oil, it does stop smoking after about 15min. So maybe rings expanding?
When I had head off, all cylinders were nice and clean, no grooves at all, but I know that doesn't mean a ring can't be bad.
Man, how could I blow head gasket at #2 and have bad cylinder?
I notice, the more days it sits, the longer it takes for smoke to clear up.

It sure does sound like classic stem seal leak but it seems a bit heavy. So you changed heads because it had a head gasket leak on #2 and now with a different head on it #2 is oil fouling still? That would seem to indicate that the problem is related to the something else other than the head. By it getting worse on #2 the longer it sit the more it indicates the head is the source though... a catch 22 here.

As far off as the odds would seem I'd still have to say something is not right with #2's valves stems or guides... I hate things like this, best of luck! :S

Just wondering if you see any difference if parked level, center stand or on a jack. The bores for the valve springs/ cam followers of course have drains. this allows the oil to return to the crankcase, otherwise it would hydrolic when the cam lobe pushed down. But from what I've seen, each bore drains towards the center, so the outboard #1 on the side stand would hold more oil.
Have you done a compression test since replacing the head and gaskets?

I haven't done a compression test since new head. I will though.
I was thinking the same as far as oil in #1 being greater on stand.
Just to check though, yesterday I parked on center stand amd today it smoked, although
not for long. I'll see if I can dig up a compression tester and check cylinders.

As you know, a compression test or leak down test may not give the results of a oil ring problem. But if you have a low cylinder still after replacing the head with a refurbished one, then that should tell you that the rings are next. Personally I've found to do the head without at least rings will result in an increase of blow by. The added compression of the fresh valve job will find its way past the next weakest link, rings. But that's just what I have learned, some of course will disagree.

xxsierraxx wrote: I just went and checked plugs and they are all good except #2. It is fouled. I started the bike, it smoked a bit and when it warmed up and was at idle I removed the plug boots one at a time. All but #2 made a difference. Kept running with #2 plug off, when I reconnected it was sputtery and a slight miss. The reason I did head change to begin with was after a leak down test I discovered keak in head gasket at#2. Was coming out at head bolt. So new head went in, gaskets etc.
Would bad rings or weak compression pull alot of oil, it does stop smoking after about 15min. So maybe rings expanding?
When I had head off, all cylinders were nice and clean, no grooves at all, but I know that doesn't mean a ring can't be bad.
Man, how could I blow head gasket at #2 and have bad cylinder?
I notice, the more days it sits, the longer it takes for smoke to clear up.

The other thing you can do is pull the carbs and the #2 intake boot and inspect the intake valve stem. If the stem is coated with blackish crud, now it's almost certain you have a bad intake valve seal and or worn valve guide.

That's a good idea as well, I am going to have to pull carbs anyway. To happen the same way as it did with old head would be too coincidental for me though. When i was preparing new head I was doing my best to check valve stem wear and i felt hey were all really tight. The thing is, even with some wear I can see some oil being pulled during vacuum,just like a vehicle, happens alot. But I can't imagine alot of oil leaking past seal into cylinder when parked, even if seal is faulty. I think at this stage, something else is going on. I think if I put a fresh head on I improved compression, as well as vacuum, so oil pulling by rings would be even greater then it was before, especiall when the engine is cold. Especially since the head gasket was leaking at #2 reducing previous vacuum even more. Bad valve stem or seal in #2 would not explain weak cylinder, rings would. As I said, I can pull #2 plug cap and notice very little drop in power. I think as the bottom end has fairly high mileage I probably need to pull jugs and do rings as well, does that make sense?

Sooo.., just to keep things entertaining, I started bike this morning, no smoke, nothing. Run like a top. Arrgh.