Header double walls

'83 KZ1100 Spectre. I have cylinder three with a suspect problem. The bike runs well now after fixing all the previous owners bad work and neglect. I go ride and come back and to check that all four cylinders are running, I spray water on each header close to the head. All but cylinder three boil off right away. Number three does boil off when sprayed, but clearly is not as hot. I can't find any real issues or reason to think that cylinder is not pulling as hard as the others. The plugs are not real even coloured yet, I did a careful bench synch of the carbs but none done yet with vacuum running. SO, my question. Do the headers have liners in them? And if they do, is it common for them to rust out of some cylinders? My thinking is that three headers have their inner liners rusted out and those pipes see full exhaust heat, and #3 has it's liner intact still, and that pipe is cooler on the outside. Maybe? I have a lot of work to do on the bike yet so pulling the pipes to see will have to wait for now.

Good thinking but probably not. The exhaust valve and header area is the hottest part of the bike, irrespective of double skinned manifolds. The colour of the headers can be telling too. You may have either a blocked pilot jet /idle circuit or ignition problem...

Swap your 2 and 3 plug leads and see if the problems transfers...if not, eliminate ignition...for now

Then think likely pilot jet blocked or pilot airscrew issues, a 4 cylinder masks this unlike a single, also with a stupidly powerful 1100 bike, 1/8 -1/4 throttle issues on one pot are much less noticeable. If cleaning the carbs doesn't sort this then maybe get the vacuum gauges and compression tester out for further diagnostics later.

In earlier posts i went through the carbs and ignition, I am sure the carbs are clean and ignition is ok on all four, but will try the 2/3 plug wire swap to see. Thing is, the headers have an appearance on the outside that shows this has been the case for some time before I got this bike. 1, 2 and 4 have light rust pitting on the headers, but 3 looks nicer.

further diagnostics then, carb fuel levels, plug chop, compression, vacuum...something pot 3 is out on.

Bench synch is a rough starting guide, but in the real world there will be a difference, hence the balance guages.

What is it like on a run when fully hot? What are the valve clearances?

The water spray on the pipes is right after a longer ride. I have ordered a cam cover gasket set so plan to look at valve clearances this weekend. It does not tick or make any noises, but a valve being held open wouldn't anyway. I am still a little suspect of the carb mounts, the kid before me used tons of silicone on the mounts and I had to clean it all off. The mounts I am pretty sure are nearly new, but are aftermarket and seem too soft, but probably seal up ok. it runs nicely, starts up with no throttle and idles good, but I can't seem to get the idle lower than 1500, and the idle screw is backed off all the way, which would sound like a vacuum leak to me, but no other symptoms of one.

There is this thing called maintenance that you may want to consider. Kawasaki felt it important to do this which is why they created a factory service manual and maintenance schedule for your bike. Vacuum carb sync, valve adjustment, and many other things are listed which can help you keep your bike running in top shape. Until the maintenance is all up to day you will struggle trying to figure out what's wrong.

Good luck

+1 on the suggestions about:

Perform the clear tube test on carb #3 to assure that the fuel level isn't too high, which could produce an excessively rich mixture from an otherwise clean and perfectly adjusted carb, resulting in failure of combustion;

Assure that valve clearances are correct for #3 cylinder, as a too tight valve may fail to seal at normal operating temperature, resulting in loss of compression and failure of combustion.

A standard compression test or leak-down test is not enough. Even if the numbers are okay, it could be that a too tight valve at cooler temp is sealing when closed, but won't seal at normal operating temp.

Good Fortune!

I am doing maintenance, but as this bike is new to me, its more repair, not normal maintenance. I set the float levels very accurately when I rebuilt the carbs, measured their heights, so I don't see why #3 would be different, and besides, it is not flooding nor is the plug black or even rich looking. I will check valve clearances this weekend, but even then, a few thou of valve held open will not make that cylinder run that much cooler at revs, sure it will change things at an idle when the flows are lower but not at 5,000, where I have been running this thing at before checking the pipe heat. And it does idle smoothly, just a bit high. I will put a vacuum guage on each cylinder next I guess, only thing that really could change that cylinder, but they were really close when I bench synched them.
Note my original statement, that #3 pipe has a cleaner appearance than the other three, that have small rust pits, this is not a new problem I have introduced due to something, I did, it WAS running like this before I got it, when it DID run last.

DGA wrote: ..... I set the float levels very accurately when I rebuilt the carbs, measured their heights.....

If you used the clear tube method to adjust the FUEL levels of the carbs; skip the rest of this reply.

If you did not use the clear tube method the FUEL levels may not all be the same. Setting the FLOAT levels by using a rule on the floats ensures the float levels are the same when dry, but it doesn't ensure the FUEL levels will all be equal when the carbs are mounted and full of fuel. One reason this is true is the fact that the buoyancy of the individual floats can vary, and that will affect the fuel levels in the carbs. The clear tube test shows the actual fuel levels regardless of any variance between the individual floats.

I'm not insisting this is causing the problem you are experiencing, but it is one more variable that should be eliminated. Ed

While idling, does detaching the #3 spark plug wire cause a noticeable difference in rpm?

Good Fortune!

I pulled the plug wire off #3 while idling and it does make a difference, yes. But I noticed that plugs #1 and #4 were leaner than the other two. And the idle won't go under 1500. The vacuum hoses for the EGR valves, or whatever that system is on top of the cam cover, goes to both of those cylinders, so I removed the hoses and capped the nipples. Big change with the idle speed, now is under 1000, maybe 700. So that system was causing a vacuum leak. So, should I just remove the whole thing and make blanker plates for the cam cover, is it ok to do it that way or?

700 rpm is too low; the engine will not maintain sufficient oil pressure. The specification calls for 1000 rpm plus or minus 50 rpm. Ed