BS34 - 75% right.........is still wrong

Greetings,  

I'm still working to get my kz1000 K2 dialed in, and it seems I'm 75% there.

I've done everything the same on all 4 carbs and 3 out of 4 are perfect.  This 4th onehas me stumped.  

I've done the followingon all carbs:

• Remove/disassemble/clean 
• Replace main jets with 4 genuine mikuni stock sized main jets 
• 4 Carb kits
• 4 New genuine Mikuni float needles and seats
• 4 New diaphragms
• Replaced non stock slide needles with 4 stock needles
• Floats all set via clear tube
• Synced carbs
• Choke seals replaced by Zed1015 (they were very bloated from apparently being exposed to ethanol)

In spite of all this, I have 1 carb (#4) that is still running extremely rich and fouls the plug within 100 miles.  I've also checked the mechanicals on #4 cylinder  

Good compression in #4
Valve clearances in spec
New valve seals
Strong spark in #4 
Valve guides check out 

Is there something else anyone would recommend that I can check on the troubled #4 carb? 

I'm out of things to try and don't want to just disassemble it again without some plan of action.  

Any nuggets of wisdom would be appreciated.  

Thanks
Scott 
 

I would do this :  spit on my glove  and touch the header to se if it it get hot. If it gets hot you have combustion and can try setting the mixturescrew more lean on that carb. turn it in until it gently seat and count how many turns it is. Check in manual how many turns out from seated it should be. If you dont find the recomeded setting try turn it 1,5 turns out then if the cylinder runs check plug after a little riding if it is white or you get popping/bacfiring from exhaust you are to lean and need to turn the mixture screw a little more out.Try quarter turns until you get a light grey sot ring on the plug. .(that takes some days of riding)
You can also after started up the bike turn the mixturescrew in and see if the engine sound changes .Then turn the screw slowly out and se if the cylinder fires.It may not fire if the plug has got fouled/wet already

Update i did a little editing in my reply because i was so tired so did not see that you wrote the plug nr4 had good spark.

Did you check the pilot jet to be sure it is the same brand and size as the other three? Does the pilot screw in that carb look damaged in any way? Broken tip, perhaps? Is the oring missing? Could the old oring be stuck in the housing? 

Thanks I'll disassemble and post some pics this weekend....

Plug chop to see which carburetor circuit is fouling your plug.
You could also try and swap your 1 and 4 spark plug wires.
There is always a possibility it could be secondary ignition wire related when the bike gets hot.

I took the offending carb (#4) apart and didn't find anything that was not consistent with the others.  I checked the jets and openings in the emultion tube with no findings. 

I decided since i couldn't swap the entire carb, I'd swap all the parts between the bad carb body and a good one (#1).  The only thing I noticed during disassembly/reassembly was the emulsion tube didn't slide out of #4, it required a bit of pressure to remove/install, other than that everything was identical.

I'll put them back on the bike and color tune it see if the issue moves to the #1 cylinder. 

The saga continues

I do not see the pilot mixture screws or related parts in the pictures. There is a spring, mixture screw, oring and cap.
These parts are in the upper left of the parts diagram, starting with part number 92066.

www.partzilla.com/catalog/kawasaki/motor...-k2/carburetor-parts

The cap is aluminum, so you may be overlooking it. To remove the caps, CAREFULLY drill a small hole in the cap so you do not drill into the top of the screw. Twist in an appropriately sized self tapping screw until it is lightly snug, then grab the screw head with some pliers and pull the plug out. You can then remove the rest of the parts and clean them and the tiny passageways.

You are on top of it when you can look at a pile of parts on a workbench and see what's missing!

You are correct,  I didn't swap those last night,  but pulled them this morning and did so.  I set them to the factory 1 1/4 and will break out the colortune later for fine tuning the idle circuit.

 

May be my eyes not right, but have you checked that the tip on the left mixture-screw is not broken off ?

I think it's more the case of just bad photography skills

Update, 

I completed switching all the internals of the offending carb (#4) over to #1.  Switched to a clean plug in #4 and put a few miles on it (<50).

The fuel soaked plug did NOT move with the carb internals,  but reappeared on the #4 cylinder.

I'm going to swap plug wires next. 

Any other trouble shooting ideas are,  as always,  appreciated. 

Cheers
Scott