Running on 3 cylinders ?

hello, i have a 1983 kz750 spectre. If i pull the plug wire off one of the cylinders with the engine running, the bike doesnt seem to sound any diffrent, but if i pull any of the others off, the bike sounds terrible. Does that mean that its not running on that one cylinder ? The bike idles fine and runs great except for a hesitation at around 3k rpms, but then pulls like crazy. Would it have any power if it was running on 3 cylinders ? thanks for the help.

Sounds like you might have the same problem I'm having with my KZ550. It's likely a problem in the pilot circuit in your carbs. My bike runs on 3 cylinders at idle, but seems to pick up the 4th cylinder when revved. I'd check the spark plug on the cylinder that's missing first, then start reading up on cleaning carbs.

it idles great and accelerates good its just around 3k to around 4k rpms it hesitates then it runs great.

The bike at first had no power at all, but i switched coils from left to right, right to left, and it made a huge differnce. i though it might be a coil probelm, but it seems it would run the same swapped or not wouldnt it ?

Check the diaphram on #1 is not holed & make sure the slider is running free (clunk test)

It's possible that a weak coil couldn't fire a fouled plug. When you swithed the good coil to the fouled plug it was able to fire through the crud and the weak coil was able to fire the good plug. You could measure the primary and secondary coil resistance and compare the two coils measurements.

Warm the bike up and then use a spray bottle with water on your pipes.
If it does not flash to steam on 1 pipe , it's cold .
Could be "ALOT" of things .
Swap 2 plugs , If the cold hole moves it's the plug .
Run it at night in a VERY dark place , give your eyes a few mins. to adjust then look UNDER the tank , Look for a blue spark ,,,,,,,,,,,
With the bike parked ,,,OK ?