KZ650. Carb #3 spitting fuel out. Wont start

You can try swapping the two coil wires, black and green.
Easy to swap.
If they are connected wrong to begin with, the spark plugs will fire, but at the wrong time.

Swap the black and green coil wires, and try to start her.

This is an electronic Ignition diagram, points also use the green and black wires:

I agree with all that has been said. You do need to see if the plug will fire or not. You could see if changing to one of the other plugs into the plug lead on #3 place it against the engine and turn it over and see if it sparks.

Beyond that if you are attempting to start it without any type of air filter on any of the carbs it will be very lean and most likely will not start.

When you rebuilt the carbs did you take them fully apart?  Soak the carb bodies in carb dip and replace the various O-rings?  Hold up the pilot jets to a light and make sure the tiny hole is open?  Check that the choke passage in the float bowl is open, and that the choke passage internal to the carbs is clear?  Check the fuel level using the clear tube method?

So I am getting equal spark on all plugs. 

I did a complete tear down and ultrasonic clean I did the compressed carb cleaner ventury clean out to clear passages in the right order as seen on this site. The float bowls were levelled with the clear tube method. 

I tried to start with and without filters without success. 

I will attempt to switch green and black but I’m not sure I detached them. 

In any case I will let everyone know what happens. 

 

Keep a fire extinguisher near by.


Especially, if you are checking spark with the spark plug outside of the cylinder.

OK went back and re-read the post and you have spark on a 4 plugs. A question I did not ask was what size jets and needle slots are you using.  Are you adding the pods or did a it come to you with them installed. Some of the less expensive pods have a lip on the rubber part that attaches to the carb that blocks or alters air flow to the pilot air jet.  If it did come to you with the pods did it run well before you cleaned the carbs up?  You can try to cover half of the carbs intake bell (upper half) with tape and see if it will start.

Will also be interested in what you learn regarding valve lash when you check it again.
 

wrote:

Will also be interested in what you learn regarding valve lash when you check it again

 

Even if one cylinder's valve clearances are grossly out of whack, if the other three are within spec (and everything else is fine) I would expect the bike to at least try to start.

Apologies if I missed it in the thread, but a compression test wouldn't be a bad idea either.

EDIT: forgot to ask the OP a question. One plug was wet with fuel; what do the other plugs smell like? Black soot can be the result of running rich or burning oil. Your sniffer should be able to tell you what's happening.

Hey guys sorry for the delay, I’ve been working. 

The reason I did the valves is that when it ran last year it was puffing light white smoke from the exhaust.

I checked the compression (princess auto/harbour freight style tester, questionable I know) and found the following results #1-140 ,#2 -140, #3-100 , #4 -100. I was advised by some people on the site to check the valve lash and adjust the shims accordingly, I have those numbers at home.

I think I have run this motor for a total of 45 minutes after putting the carbs back together (I have the new jets and needles info at home as well) and installing new plugs.

The #3 plug was sooty and soaked with fuel, the other 3 were just sooty. I wouldn’t say the soot was that bad as you can see in one of the photos. 

The motor had pods when I bought it but I did get new cheap ones but I don’t see any obstructions. 

Check the obvious things first.  Is the float valve closing correctly?  Does the float move up and down correctly?  And is the float sticking against the side of the bowl?  Is your overflow plugged?

Thank you , I definitely will.  But presently unable to get at it due to work 

Not to sure if this makes sense but this is how I wrote it out

Something is not right with compression in #3 & #4.  But that wouldn't prevent the engine from starting or the carb from flooding.

Just to be clear...when you increase the shim size you decrease your valve lash.  For example, when you went from a 270 to a 275 on cylinder #1 front, you decreased the clearance from 0.12 to 0.05.  I don't have the book in front of me but from memory I think you want about 0.15 valve lash.  Did you check after you changed shims?