Engine races when choked

If not the pilots (I doubt it) it could be air leaks behind the carb holders.
Steve

Thanks for all the suggestions.
I don't really know the vintage of the carb holders. I can still get new Kawasaki parts from Partzilla, and with a 34 year-old bike you're better off replacing anything you can while you have the chance. So I'll start with them, and see where that gets me.

Does anybody know what the difference between 16065-1131 and 16065-1135 is? They both say they're used on the '83 KZ1100-D2 Spectre.

Mine does the exact same thing. Carbs are spotless, synced and tuned with a colortune. Valves are adjusted. Once it warms up there are no issues and it runs great. I let it warm up with my hand on the choke handle adjusting it so the engine doesn't race or die. Usually after a few seconds I can push it in to the 2nd détente and it will idle just fine.
I've learned to live with it.

padarjohn wrote: Thanks for all the suggestions.
I don't really know the vintage of the carb holders. I can still get new Kawasaki parts from Partzilla, and with a 34 year-old bike you're better off replacing anything you can while you have the chance. So I'll start with them, and see where that gets me.

Does anybody know what the difference between 16065-1131 and 16065-1135 is? They both say they're used on the '83 KZ1100-D2 Spectre.

You should check the carb holders for leaks. They will eventually develop tiny cracks in the mating surfaces between the holders and the cylinder head that can cause them to leak at idle. These cracks cannot be seen with the carb holders in place. I suggest you try the following. Get the engine warmed up and temporarily set the idle as low as possible without killing the engine (lower than 900 rpm if possible). The lower the better because with the idle very low the slides are nearly shut and the vacuum inside the carb holders is at its highest. Then spray carb cleaner around the carb holders, especially where they mate with the cylinder head and where the carbs attach to them. Carb cleaner works best for this test as it doesn't leave an oily mess with WD40 or evaporate so quickly that it is not drawn into the leaks as can happen with propane or starting fluid (ether). If the engine dies or reacts to the carb cleaner, you need to replace the carb holders. Carb holder leak related problems are noticeable at idle but generally don't have much impact when riding because the throttle is open. If you find you need to replace the carb holders soak the screws with Kroil for a couple days before attempting to remove them, and use JIS standard, NOT Phillips, screwdriver bits, and this will greatly improve the odds that you will not break or strip a carb holder fastener as so many have done. Let me know if you need info on JIS bits, I have a good link for making your own at no cost.
Ed

Leaking carb boots don't cause a high idle under choke. They cause a hanging idle once the bike is warmed up. If the carb boots are original it's money well spent updating them regardless..

And no disrespect to Ed's recommendation, but spraying stuff on carb boots is not a definitive test to see if they are leaking. That test show only gross leaks, not small ones.

Replace the boots. Small leaks will have a effect on how it acts at closed throttle, choke, idle, etc.
Steve
jetsrus.com/mounting_flanges/mounting_flanges.html

Following up,...
I got the new carb holders and finally got around to poking at it again (either not enough free time, or just too %$@$ hot).
Now that the carbs are off the bike again I started looking a little closer at them. When I got the bike they were dirty, flaking/chipped paint, etc. so I had just taken them off, packed them up, and sent them off to Rick be rebuilt. When they came back I didn't really pay much attention, I just stuck them back on, balanced them and set the idle.
Looking closer now, though, I realize that the plugs over the pilot screws are missing. I started playing with them, and they were all set at roughly 1 turn out. I checked pictures I had taken before sending them off and they were missing then. I suspect Rick just put them back at the same setting they were at when he got them.
They're supposed to be nominally set at 2-1/2 turns, all other things being normal.
So I'm thinking this has been the problem all along. I'm guessing that the idle was really lean, and the idle speed was adjusted to compensate. When the choke kicks in the richer mixture it takes off.
It may be a little while before I get everything back together, as I'm still ordering/replacing parts. But when I do I'll report back.

A cold engine, is dependent of the inner friction, and need a less or higher idle to stay alive.
The carb adjustment can be very unique and differ from stock adjustment.
A lot of deviations in the fuel mixture environment can lead to different solutions for a good ruining engine.

Mine does the same thing with the choke, sits around 3,500 to 4,000 rpm after a half a minute or so. I figure it's just warming up the engine to operating temperature faster. I let it sit there until I can push the choke in and the idle's at 1k and not lower.

During the motor rebuild I had the carbs get a once-over cleaning and the high idle went away for something like 2 weeks before returning. Considering it's at 4,000 rpm anyways going down the highway I've never been all that worried about it. Something's up with the carbs, but I'm not about to rip them apart and potentially cause even a bigger issue over a problem that isn't that serious. From the sounds of other comments in this thread it's a pretty common and overlooked thing.

My 83 KZ550 on full choke when first start in the morning, will rev to 4K rpm. Starts instantly. I have tried to find a choke lever position that will idle less but can't seem to find one. So I just start it up, push it out of the garage and hit the road. As soon as I hit about 2nd gear the choke goes all the way in and I'm good. It will idle about 800 for a few minutes but before I've ridden 1 mile it's back to normal. I'm just happy it starts and runs so well.

I know it's been a while, but I didn't want to leave this issue unanswered.
The problem was, indeed, the pilot jets. I adjusted all four to initial recommended settings (2-1/2 turns), then started the bike and adjusted each one for optimal idle, one at a time.
The bike now behaves when choked the way I remember it should.

Sorry it took me so long to get back here.