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1982 Kawasaki KZ750 LTD only runs on choke

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14 Jun 2021 19:09 #850206 by don3194
Okay, First things first, this bike has a carb set from a 1983 Kz750 Shaft drive like, this one here:
www.partzilla.com/catalog/kawasaki/motor...0-f1/carburetor-part  
This set was WAAAYYYY better than the original one to the bike, someone had truly f'ed up the old set beyond it being useful

So I basically swapped everything over from the original set except I swapped out the jets for #100 jets like the diagram showed. After fussing with the fuel bowl positions for the longest time, I finally got it set to 4 mm below the bas of the carb. It would run and high idle on choke and even rev but the revs would hang up high for a while. I would take the choke off and it would idle down to a smooth idle, but die after around 15 seconds. It would die instantly if you tried to rev it without choke. 

Now today I tried something and swapped the original #125 jets into and it still only runs on choke. But now it doesn't rev hang when you rev it on choke. When you take the choke off the engine speed goes way up to 4,000 without any input. And when it does start to go down you can't rev it up any, it will just die again. 

I tried the 60/40 trick again and it was hard to tell if there was a difference.

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14 Jun 2021 19:58 #850209 by Nessism
Replied by Nessism on topic 1982 Kawasaki KZ750 LTD only runs on choke
Is the airbox installed and did you replace the rubber carb holder boots?  Where are the pilot screws set?  Vacuum sync?  

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14 Jun 2021 21:13 - 14 Jun 2021 21:13 #850211 by don3194
Replied by don3194 on topic 1982 Kawasaki KZ750 LTD only runs on choke
Airbox is installed, carb rubber boots have not been replaced, I can't remember where the pilot screws are set for sure. And I have not checked vacuum sync on this carb set yet.

In regards to the pilot screws, where should they be, I think they're like 3 turns out? But it could 1-1/2 I can't remember now, I have touched them in the few weeks I gave up on the bike.
Last edit: 14 Jun 2021 21:13 by don3194.

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16 Jun 2021 14:47 #850292 by tdogm6@yahoo.com
Replied by tdogm6@yahoo.com on topic 1982 Kawasaki KZ750 LTD only runs on choke
Is the petcock allowing full fuel flow? 

1980 KZ750G

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17 Jun 2021 18:40 #850333 by don3194
Replied by don3194 on topic 1982 Kawasaki KZ750 LTD only runs on choke
You know I haven’t checked that, I guess I just assumed it was flowing. I will have to check that tomorrow.

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17 Jun 2021 18:51 - 17 Jun 2021 18:59 #850334 by F64
You mention the 60/40 test. Did you use tape or just your choke?
And did you create an air leak for the test as well?

81-KZ440-D2.
Louis Dudzik's GM HEI ignitor conversion installed 2015 s3.amazonaws.com/gpzweb/Ignition/GPZgmHEImod.html
Motogadget m-unit blue installed 2017.
LIC, NY
Last edit: 17 Jun 2021 18:59 by F64.

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22 Jun 2021 18:16 #850612 by don3194
Replied by don3194 on topic 1982 Kawasaki KZ750 LTD only runs on choke
Its been a while since I have done the 60/40 test but yeah I taped the air filter and my airleak was just removing the airfilter and cap. 
I am still working on it, but I'm just waiting on new carb boots so I'll repost how it turns out with new ones. They should be here saturday.

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23 Jun 2021 19:47 - 23 Jun 2021 19:48 #850683 by F64
The lack of any change with the 60/40 test may have me looking at something other than the intake side of the cylinder head.
Possibly ignition, exhaust or electrical.
 

81-KZ440-D2.
Louis Dudzik's GM HEI ignitor conversion installed 2015 s3.amazonaws.com/gpzweb/Ignition/GPZgmHEImod.html
Motogadget m-unit blue installed 2017.
LIC, NY
Last edit: 23 Jun 2021 19:48 by F64.

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