Still Chasing missing issue

I have posted different questions related to this before and have updated information to work off of.  82 KZ1000J, At times it seemed to be low on power or missing.. I started looking at exhast temps to try and narrow it down #2 running 200 degrees less than others. I have put in new plugs, new wires, new caps, rebuilt carbs. recleaned again and put in new shaft seals, new rubber boots, new coils. I had run compression test. I bought a leak down qauge. I have rechecked valve clearance. #1 Int .152 Exh .178  #2 Int .203 Exh .152  #3 Int .203 Exh .152  #4 Int .178  Exh  .152. 
 Compression #1 135, #2 135, #3 140, #4 130.  Leak down all less than 10%, only hear leaks around rings but not much.
I can move plugs, wire, coils to see if it follows. I can go thru the carbs again, but can't swap them.
Would a bad igniter cause one plug to miss fire? I don't believe so. 
Where should I look next?

Did you vaccum sync the carbs?

Things to consider. That's a considerable temp difference for sure. Check to see if your tank petcock sources it vacuum off #2 carb. A failed petcock diaphragm can fail in a couple ways but still "appear" to work. Two independent chambers, metering fuel side and vacuum side. Vacuum side can be pinholed but still allow enough supply to pull o-ring off it's seat and allow fuel to flow. In this case it's more of a lean/air leak. The other is a pinhole in fibre of material and it sucks raw fuel into that #2 port causing a rich condition. Be weary of this scenario, you can fill your crankcase with fuel even without even running. To check, pull source hose off petcock and plug it. Set lever to "prime" and recheck temp test. Could be sync of carbs too if checking temps at just idle? Pull that cylinder sparkplug and have a look too. Several other things too but start with the easy stuff.   

Run it again.
When the #2 cylinder measures 200˚ lower kill the engine, let the engine cool down and pull the plugs.
What do your plugs look like?
Is this just at idle?
Are there certain rpms where the #2 cylinder comes back online?

You might want to consider "choke plungers" there have been many suggestions ref "lean" but generally lean runs hotter (just a suggestion)

Yes I still have a mercury stick I use all the time.
OK I get  the petcock issue and can check, but usually I'm running off a small gas jug hung over the bike.
Bike has sat since about October. Since the rings and valves check out I will work my way back up and can see what happens.
Choke plungers, I did not use the new ones in the rebuild kit as they looked different. BUT I can switch those from carb to carb to see if the problem moves.
Thanks!
Ken

Back together. Put the valve cover back on, remounted carbs and with the choke on it started and ran. RPM were high but if I tried to go to Half choke it would die. 
If I put my hand over the carb inlet on 1,3,and 4 ir would suck in my fingers and try to die if I didn't move them.
On #2 it would only slightly suck in my fingers and there would not be much difference in running.
This is why a elected to do a leak down. I will double check the spark plugs and wires etc. by switching them around.
Would a too wide valve gap cause issues? I didn't thing it would and was going to re shim later.
If it's determined to Be carbs I may send them to Oldskoolcarbs for a rebuild. Any feed back n him?

A lack of suction suggests an air leak 

 

OK so went out today. Started the bike with a full choke ran at over 2000rpm, if I adjusted it do it would eventually die. Half choke it would die. Sprayed Starter fluid no real change. 
Vacuum check by taking off caps and attaching the gauge one at a time. #4 picked up RPM with cap off. none of them would give a steady reading.
I leaning back to carbs, even though I have cleaned them a few times. What would a diaphragm with a hole cause?

I also checked leak down again start with 61 psi and would leak to 54 or 53 psi and hold there. so about 12% roughly.

These engines will run with that kind of compression, but its not optimal.

Can you confirm spark intensity? There are tools to measure spark length across a gap.

I once had a bad OEM igniter that gave a weak spark, that and the sub optimal compression is not a ideal running condition. Would run but not "snappy", weak spark and compression is not going to make power.

12-15% leak down on a street engine is just about where you would consider a top end rebuild.

After Looking at valve adjustment, compression, and leak down, which all were at least ok I went back to carbs. I found some stuck pieces, so recleaned all of the carbs.
I did the liquid electrical tape trick on a couple diaphragms that appeared to have some pin holes. Between all of those and checking the float levels I was able to get the bike to fire right up an idle without the choke.
Synced the carbs and it's doing fairly well. #1 header is still much higher temperature than the other 3. I think this is related to #1 carb having the worst diaphragm, and it's running lean.

Has anyone used the JBM replacement diaphragms? Looks easy enough and much cheaper than buying new slides.

Also where can I get the small slotted "screw" that is used to adjust the idle speed? The one with the Nut on it? I had one side of one of them break off.