TOPIC:

My '83 KZ1100 LTD is running on 3-cylinders after being garaged for the winter. Started up fine and it ran on 4, then dropped the #2 cylinder within 10 minutes of riding. I know this is not an uncommon issue, and I've gone through the basics. At this point I'm hoping for advice on whether I'm heading in the right direction. Pretty new to working on big bikes.

I swapped plugs, caps, wires, and the problem remains on the #2 cylinder (checking pipe temp).

Is it possible the float is stuck open and the cylinder is flooded? Strong gas smell. With the #2 plug removed a bit of fuel shot out when I turned it over. Plug is wet.

Best way to fix this is to remove the carbs and check if #2 is stuck? Anything else I should be looking at?

Any assistance or advice appreciated.

You might be able to lightly tap on the bowl to dislodge it. I now have allens so I can take them off one by one.
Steve

Thanks for the reply. I tried that. Drained the carb and tried it that way as well. No luck. Think pulling the carbs is the next step?

Anything I might be missing?

You say you swapped plugs caps and wires, is that because you had spark issues?

Or....have you confirmed you have good spark?

Chris

Yeah, the carbs need to come off. Might as well do it now, the season is ahead. Check the pilots and Put your finger over the vent for the diaphragms to see if they drop or come down slowly. Clear the needle valves and seats. Do the clear tube test for the floats. You won't be disappointed.
Steved

Most of the time if the cylinder is flooding due to debris in the needle and seat of the float system, that cyl will still fire poorly with the throttle cracked open half way or more. If you have spark at that cylinder, but no heat on the pipe in question, it sounds a little more like a plugged main jet and or float is stuck with the needle closed.
In other words no gas in that bowl.
By the way, we are all just shooting in the dark, of course, but all these suggestions are good for trouble shooting.

Yup.

Visible spark on #2 but to be sure I swapped the plugs between #1 and #2. #1 still fired, #2 still dead. Not the plug. Then swapped plug wires. #2 still dead. Definitely gas in the bowl and the cylinder.

I left it on the side stand over-winter which I usually don't do. I'm assuming the #1 and #2 carbs are gummed up.

Looks like the carbs are coming off! I'll do the clear tube test and clean as needed. I like to take this bike on long trips and appreciate any peace of mind available. Thanks for the suggestions!

Pay close attention to the pilots. They're the first to get clogged up.
Steve

Update -- took the carbs off and cleaned them. They were pretty clean to begin with but I replaced the needle valves and some questionable o-rings. Time hangup was the carb airbox boots which were pretty stiff and needed to be replaced. Hard to find but got some the other day.

Carbs went on this morning and it fired up on 4 cylinders. Then sputtered and stopped. Restarted and #2 wasn't firing again. #2 plug has good spark and the float bowls were full but the plug was wet with fuel. I noticed some fuel leaking from the petcock, near the vacuum intake. It's leaking from the petcock itself not from the fuel lines.

My current theory is the petcock vacuum tube that goes to the #2 carb is flooding the cylinder and fouling the plug, keeping it from firing. It fired up at first because the carb was clear. Sound plausible?

Ordered a new petcock. I'll blow out the vacuum intake on the #2 carb when I install it. Feeling optimisic.

More than plausible. That is not an uncommon problem with vacuum petcocks. When the petcock has a problem fuel can sometimes pass through the vacuum line to the #2 carb and cause exactly the problem you describe. If you found any fuel at all in the vacuum line something was wrong inside the petcock. Ed

Excellent! Even more optimistic now.