1983 kz1100 Ltd running on 2 cylinders

Need some help figuring out my problem. I have good spark, compression and fuel to all 4 cylinders. I can start the bike with carb cleaner and it will idle and I can even drive it around. I think its only firing on two cylinders because only 2 headers get hot, numbers 3 and 4. 1 and 2 stay cool and when I check plugs they appear wet with fuel. I've put in new plugs with no difference. Swapped plugs with no difference. Swapped wires between 2-3 with no difference. Swapped cdi with no difference. I'm about to check my valve clearances. Could that possibly be my problem? Any other ideas come to mind to check? The 2 cylinders do fire with carb cleaner. Thanks for any help.

Hi Willy,
Good compression doesn't mean that your valves are correct but most likely means that they're not causing your problem.
Have you checked the fuel level in the float bowls by the wet/clear tube method? I believe that alcohol in gasoline attacks the foam floats and makes them heavier. This means that checking the float height with the carbs up side down doesn't give and meaningful information. I can't tell you how many times I heard that the left side cylinders weren't firing and the cause was too much fuel.
Good Luck
Bill

Even with the fuel levels at the correct height you may still have problems with blocked jets.

Good Luck

Bill

Thanks for the help. I was wondering about it possibly getting too much fuel. Would the carb cleaner still fire even if it had too much fuel already? I didn't think the valve theory made a whole lot of sense but I came across it to n another forum where the guy was having the same problem. Guess I'll check the fuel level before going after the valves.

willystyle56 wrote: Thanks for the help. I was wondering about it possibly getting too much fuel. Would the carb cleaner still fire even if it had too much fuel already? I didn't think the valve theory made a whole lot of sense but I came across it to n another forum where the guy was having the same problem. Guess I'll check the fuel level before going after the valves.

Hi Willy,
You said that you were able to get 3 & 4 to fire with the carb cleaner. It could be that 3 & 4, being higher when the bike is on the side stand, are not quite as flooded out as 1 & 2. Just because too much fuel is being drawn through the main jets doesn't have anything to do with how the idle or low speed jets may or may not be working. It's possible that you're not getting any atomization out of the low speed system and the carb cleaner is filling that gap and allowing the engine to run.
All speculation. Have you pulled and cleaned the carbs? How clean is the tank?
Best of luck.
Bill

if you get the cylinders to fire with carb cleaner then it sounds like it needs fuel to those cylinders

The carbs were off the bike when I got it and were partially torn down to clean because it had been sitting for years and ran like crap from what I was told. I cleaned them some and had to replace a float needle and valve in one carb because the needle was stuck in the valve. Put them back on and it'd barely idle so I took them off to clean them more. Discovered a plug needed to be removed to get to the pilot jet and there was all kinds of gunk in there right under the plug. Cleaned that out, sprayed cleaner through the passages and that's how I got to the point I'm at now. Haven't checked the float level yet but seems like it will be off with the carbs again.