KZ1100 spits and won't idle

If you have an air compressor, you could pressurize #3 to see if compression is escaping through the valves, gasket, cylinder walls or rings.
Basically, a leak down test without the gauge.
Just use your compression tester hose if it has a quick disconnect fitting on the gauge end.
You have to listen where the air is escaping..intake, crankcase, cylinder head, exhaust pipe.

I don't yet own an air compressor to check where air is escaping from but will keep that in mind after I purchase one one day.

Yesterday, I found a slight incline in the new fuel line apparently causing an obstruction to the free flow of fuel.  I trimmed it and bike runs even better at warm idle.

The award for the solution to the main problem which prompted the post goes to Mikaw for suggesting boot replacement.  I can't stress enough to someone resurrecting an old bike to replace them; a quality non-Chinese set aren't that expensive.  Checking for cracks is useless; mine weren't cracked but had lost all elasticity.

Any time is good time spent to refine carburetor balance and jetting.
I thought my engine was running optimally until trying one Pilot Fuel Jet size larger, and one Air Jet size leaner (larger).

Now I know we're getting close...and again am reminded that there is always room for improvement.