KZ1100 3-cylinders firing

Can test by removing petcock vac line from carb, plug/cap the carb vac nipple, and test run with petcock set in PRIme position.

This will eliminate any fuel leakage through the vac line from carb to petcock.

Good Fortune!

Yeah and you can ride it too. :woohoo:
Steve

I replaced the diaphragm on my petcock last year after having this same problem. Let me put something out on the table since I am having the same issue once again - and just realized I should check the vacuum hose for fuel.

Would storing the bike over the winter months with a full tank of gas and Sta-bil have something to do with deterioration of the diaphragm? The problem seem to have returned after going through that first tank of fuel containing Sta-bil, and I can smell a faint fuel scent.

Just wondering...

I'll conclude this thread by saying that the problem is solved and it was indeed the petcock. Replaced with a new OEM petcock (purchased from Z1) and a new plug. I opted not to rebuild the petcock because it was leaking from the side -- actually blowing fuel bubbles -- and from what I understand, rebuilds are not always successful. New petcock cost about $75. Rebuild kit was $50. Started right up on 4 cylinders.

Bike runs better than ever partially due to a better seal from the new carb intake boots. Not only do they seat better, but I didn't even realize the airbox could be moved forward -- the last owner had it in a mid/back position and the boots were barely hanging on.

I was about to go for a lengthy ride and noticed the sidewall of my front tire is badly cracked. It's not even that old. Just dropped the fron wheel off for a tire change. Can't win this year, I guess.