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82/3 KZ750 LTD H4 rebuild question

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13 Aug 2024 14:54 #903211 by twinhcarbs
82/3 KZ750 LTD H4 rebuild question was created by twinhcarbs
Hey forum, ty for adding me. I am a full time mechanic and part time motorcycle restore/rebuild guy. I have worked on numerous Hondas and I have them down. This is my first Kawasaki and it has taken me thru the ringer.  Motor has a fresh rebuild/reseal has great compression across the 4 cylinders. I have spark and fixed the couple issues with harness, factory carbs rebuilt twice and used all factory parts. Has air box original exhaust etc. fuel line was gone, and this is where my problems start. I am currently using a portable gas tank to dial in the carbs. I have all brass fittings not 100 on size as I’m not at my shop but for sale of argument lets say 3/8 to 1/4 tee and then two more 1/4 tees splitting the line to remaining two carbs. And when I fire it up I swamp mandatory one carb that fuel favors. I then take the line and do bench test with cups to see if fuel is favoring and how to address it. I have all equal sections of hose and when I do bench test it favors one line for sure every time. I do understand that carbs will naturally pull vacuum and help pull fuel to all 4 but no matter where I put the main split it’s a lost cause. On Hondas they have one fuel line and the carbs share a “rail” of sorts and I rarely have a flooded cylinder issue. I’m about to order the Murray carbs so I will have two carbs to feed and call it a day, but wondering what do u guys use for ur fuel lines, and has anyone had this issue before? When I searched I didn’t find this exact question so figured I’d post.  Any help will be appreciated friends. 

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13 Aug 2024 18:30 #903224 by Nessism
Replied by Nessism on topic 82/3 KZ750 LTD H4 rebuild question
Those carbs should be Keihin CV34's.  I've rebuilt a good many sets of them.  They are a little more tricky than Mikuni CV's, but not too bad.  I have O-ring kits for them too.

Sorry, but I'm not following what problems you are experiencing.  Can you explain again?

[img
P1010509 by nessism , on Flickr

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13 Aug 2024 18:57 #903225 by TexasKZ
Replied by TexasKZ on topic 82/3 KZ750 LTD H4 rebuild question
There is only one fuel inlet. You can see it in the picture between carbs two and three. Are you connecting fuel lines to the bowl vents instead?

1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough

www.kzrider.com/11-projects/620336-anoth...uild-thread?start=24
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14 Aug 2024 02:42 #903237 by twinhcarbs
Replied by twinhcarbs on topic 82/3 KZ750 LTD H4 rebuild question
On my bike it has no shared fuel rail it’s individual fuel nipples. I’ll get pics today. But out of 4 carbs no matter which way I make the fuel line to split it 4 carbs one gets sent all the fuel. And the other 3 lean.  

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14 Aug 2024 05:03 #903243 by Nessism
Replied by Nessism on topic 82/3 KZ750 LTD H4 rebuild question
This is the other side of the carbs.  Are you putting fuel into the angled brass nipples?

[img
P1030288 by nessism , on Flickr
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14 Aug 2024 09:16 #903255 by TexasKZ
Replied by TexasKZ on topic 82/3 KZ750 LTD H4 rebuild question
In the photo below, inside the red circle is the fuel inlet T. As you can see, it feeds carburetors two and three directly. The two red arrows point to the fuel transfer tubes. Only a tiny bit of each is visible. They transfer fuel from two to one and from three to four.


1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough

www.kzrider.com/11-projects/620336-anoth...uild-thread?start=24
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14 Aug 2024 09:22 #903256 by TexasKZ
Replied by TexasKZ on topic 82/3 KZ750 LTD H4 rebuild question
On the engine side of the carburetors are the fuel bowl vents. They are circled, sloppily, in red below. Each one of these should have a separate hose attached. Typically, they drape over the carburetors, and sometimes over the air filter box, and terminate below and between the swingarm pivot and the frame cross member in front of it. Their purpose is to supply atmospheric pressure to each fuel bowl as needed,


1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough

www.kzrider.com/11-projects/620336-anoth...uild-thread?start=24
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14 Aug 2024 13:30 #903263 by JR
Replied by JR on topic 82/3 KZ750 LTD H4 rebuild question
Actually on the Keihin CV34 carbs for the 750/4 those red circles above are around the brass vacuum nipples which if no clean air system then cap 3 and connect the 4th (usually #2 carb) to the smaller vacuum nipple on the petcock. If no petcock then cap it also. 
As Tex said, only connect fuel line to the black T
 

1980 kz750E1, Delkevic exhaust
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14 Aug 2024 14:14 #903266 by Nessism
Replied by Nessism on topic 82/3 KZ750 LTD H4 rebuild question

Actually on the Keihin CV34 carbs for the 750/4 those red circles above are around the brass vacuum nipples which if no clean air system then cap 3 and connect the 4th (usually #2 carb) to the smaller vacuum nipple on the petcock. If no petcock then cap it also. 
As Tex said, only connect fuel line to the black T

 
Correct.  

On the later year CV34 carbs, Kawasaki added dedicated float bowl vents, which flowed into small plastic Tee's, one between 1&2 and the other between 3&4.  
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14 Aug 2024 14:18 #903267 by Wookie58
Replied by Wookie58 on topic 82/3 KZ750 LTD H4 rebuild question
Is it me or does something about this post not "smell right" I don't know any "full time mechanics" that would make this error (as it appears i being made) it's a miracle that it hasn't hydraulic'd the motor and bent a con-rod or set the shop on fire (the gas must be pouring through the carbs !!!!!!) I also don't get the attraction of spending a significant amount of money on a twin carb set up to reduce the performance when apparently the stock air box etc is present ???? maybe I just don't understand !!!!
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14 Aug 2024 14:32 #903268 by twinhcarbs
Replied by twinhcarbs on topic 82/3 KZ750 LTD H4 rebuild question
I worked on two choppers ( mostly customer was getting full dip) and 3 customer hondas.  I rebuilt these carbs in 22 with all cmsnl parts. I am feeling supremely humbled.  You are correct, it didnt smell right to me either, but just scrolled thru all my pics from when I rebuilt them, and the fuel filler plastic tee is right there in the middle.  I installed them into the bike, and then got side tracked after, and put this bike on the back burner.  I recently just tried to fire it up, and I hooke the fuel to the feed line, on last honda I did the main feed was right at that same spot and was brass fitting as well.  I got this bike from a guy and it was outsiode for 20 years.  So I havent been devoted to it, or spent any sequential time, was always doing one part, and then working on another so I am just a complete moron.  I ty u all for the help sincerely,

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14 Aug 2024 14:37 #903269 by Wookie58
Replied by Wookie58 on topic 82/3 KZ750 LTD H4 rebuild question
Everybody makes mistakes but it takes a "strong character" to publicly admit when they "dropped the ball" respect and good luck wit getting it sorted 
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