1981 KZ1000J CARB ISSUES NEED ADVICE

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Re: 1981 KZ1000J CARB ISSUES NEED ADVICE

01 Feb 2019 08:53
#798034
Hey Steve, The baffle is not removable. It may very well be baffle material. I do have a video of the exhaust outlet during initial start and the fireworks were quite impressive lol. The bike has been sitting for 10 years without the exhaust on so it is entirely possible that a critter got in there and made a home. I did get quite a bit of rust out when I shook it to get the rust out before installing. I did a cold start yesterday and it fired right up. I need to let it run for a bit tomorrow as it tends to stumble a bit on #4 and hopefully by letting it run, the carbs passages will get cleaned out a bit more and I can get it color tuned. Have a good one and thanks for your reply. Jon

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Re: 1981 KZ1000J CARB ISSUES NEED ADVICE

01 Feb 2019 08:57
#798035
The pilots are very small. You can use a strand from a wire brush or guitar string to clear them. Without the pilots being clear it won't run for SHT.
Steve
Z1b1000 1975 Z1b
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229
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Re: 1981 KZ1000J CARB ISSUES NEED ADVICE

04 Nov 2024 10:59
#905767
Nessism wrote:
The pilot screws should be set to 2.5 turns for a start. Be sure to remove the screws entirely before soaking in carb dip.
Nessism, I was wondering why 2,5 turns for a start. I believe the manual states 1,1/4 turn to start with. I have to say I trust you more than the manual; but would like to understand the reasoning.

I am now at 1,1/4, and my bike seems to be very rich. Would going to 2,5 make it leaner or richer?

Thank you!
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Re: 1981 KZ1000J CARB ISSUES NEED ADVICE

04 Nov 2024 11:36 - 04 Nov 2024 11:56
#905769
Carlos are you using the jetting and needles from your original carbs or the replacements, you posted that your mains are 127.5 which according to the info Daveo posted is for a "J"
"J2 jetting and needles are different because the "J" uses bigger cams to produce the additional horsepower over your "K" model (CMNSL's data also suggests the adjustable needles you have are possibly not right for your model ?)
It's also possible your choke plungers are leaking (Zed1015 reconditions those)

1982 KZ1000 Ltd
www.kzrider.com/forum/11-projects/617631...-82-begins?start=192
kzrider.com/filebase-alias?view=download...d-fault-diagnosis&ca
Last edit: 04 Nov 2024 11:56 by Wookie58.
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Re: 1981 KZ1000J CARB ISSUES NEED ADVICE

04 Nov 2024 17:28
#905775
cartal wrote:
Nessism wrote:
The pilot screws should be set to 2.5 turns for a start. Be sure to remove the screws entirely before soaking in carb dip.
Nessism, I was wondering why 2,5 turns for a start. I believe the manual states 1,1/4 turn to start with. I have to say I trust you more than the manual; but would like to understand the reasoning.

I am now at 1,1/4, and my bike seems to be very rich. Would going to 2,5 make it leaner or richer?

Thank you!
The pilot screws control how much fuel emulsion is allowed in at idle and just off.  More open = richer.  Kawasaki set the carbs very lean, for emissions purposes.  In my experience. 2.5 turns open is a good starting point.  After you get the bike up and running properly, carbs synced, then tune the screws at idle until you achieve the highest idle speed.  It's very possible that the idle speeds up with turning in the screws, but you won't know this until you start the process.  For most, rich runs better than lean.  If your carbs are running rich with all factory jetting, and the airbox, that suggests something is wrong.  Fuel level too high and/or leaking float needles, leaking choke plungers, stuff like that.
Ed
Carb O-ring Kits : www.kzrider.com/forum/3-carburetor/61807...-o-ring-kits?start=0

www.kzrider.com/forum/faq-wiki/618026-new-owner-things-to-know

1981 KZ750E2
www.kzrider.com/forum/11-projects/604901...z750e-project-thread
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Re: 1981 KZ1000J CARB ISSUES NEED ADVICE

31 Dec 2024 06:15
#907353
Wookie, I´ve opened another carb thread, as I don´t seem to be able to get the carburation right. @Zed1015 mentioned choke plungers, which you already said, but something you said (and I am replying to) made me think.

No, I am not using 127,5. Those are the jets Jim´s carbs had, I am using the 122,5 jets that came with my bike. These are a bit peculiar, as they are not the good old brass jets, but rather a plastic copy of those brass jets. They do have 122,5 imprinted on them, but I just realized now that, being plastic, perhaps they have been "played with" before and the real size is not 122,5 anymore, but something else.

I don´t have any other 122,5 brass jets, but looking over in my old parts, I´ve found a set of 120´s. I´m thinking of trying these, and seeing if the plastic ones are off by a lot, or if there is no really significant change, it is really just the choke plungers (which I may change anyway).

Any thoughs on this? 

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Re: 1981 KZ1000J CARB ISSUES NEED ADVICE

31 Dec 2024 06:56
#907355
I'm not Wookie but those "plastic" main jets are a relic from the past, just like these double balled float needle replacements. Some stuff from the 80's that persons came up with with Great intention but never functioned in the real world. I've thrown away all that assortment of plastic mains i'd had years ago, suggest you do the same.    
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Re: 1981 KZ1000J CARB ISSUES NEED ADVICE

31 Dec 2024 10:01
#907362
cartal wrote:
Wookie, I´ve opened another carb thread, as I don´t seem to be able to get the carburation right. @Zed1015 mentioned choke plungers, which you already said, but something you said (and I am replying to) made me think.

No, I am not using 127,5. Those are the jets Jim´s carbs had, I am using the 122,5 jets that came with my bike. These are a bit peculiar, as they are not the good old brass jets, but rather a plastic copy of those brass jets. They do have 122,5 imprinted on them, but I just realized now that, being plastic, perhaps they have been "played with" before and the real size is not 122,5 anymore, but something else.

I don´t have any other 122,5 brass jets, but looking over in my old parts, I´ve found a set of 120´s. I´m thinking of trying these, and seeing if the plastic ones are off by a lot, or if there is no really significant change, it is really just the choke plungers (which I may change anyway).

Any thoughs on this? 
You could try the 120's but I would do the choke plungers anyway given their age. Just be wary it's winter right now and colder denser air will make it run leaner anyway so with smaller jets it may run hot (I know you are in Spain so probably not as cold as here !!)
1982 KZ1000 Ltd
www.kzrider.com/forum/11-projects/617631...-82-begins?start=192
kzrider.com/filebase-alias?view=download...d-fault-diagnosis&ca

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Re: 1981 KZ1000J CARB ISSUES NEED ADVICE

31 Dec 2024 11:33
#907366
cartal wrote:
. These are a bit peculiar, as they are not the good old brass jets, but rather a plastic copy of those brass jets. They do have 122,5 imprinted on them, but I just realized now that, being plastic, perhaps they have been "played with" before and the real size is not 122,5 anymore, but something else.

I don´t have any other 122,5 brass jets, but looking over in my old parts, I´ve found a set of 120´s. I´m thinking of trying these, and seeing if the plastic ones are off by a lot, or if there is no really significant change.
Get rid of those plastic jets and fit brass.
Plastic ones are garbage and well known for not having an accurate flow rate anywhere near what is printed on them or the equivalent brass.
AIR CORRECTOR JETS FOR VM CARBS AND ETHANOL RESISTANT VITON CHOKE PLUNGER SEAL REPLACMENT FOR ALL CLASSIC AND MODERN MOTORCYCLE CARBURETTORS
www.kzrider.com/23-for-sale/611992-air-c...lide-mikunis?start=0





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Re: 1981 KZ1000J CARB ISSUES NEED ADVICE

01 Jan 2025 22:57
#907437
asphalt900 wrote:
I'm not Wookie
my apologies, Asphalt!

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Re: 1981 KZ1000J CARB ISSUES NEED ADVICE

01 Jan 2025 23:04
#907438
Guys, happy new year!

Back to the thread, I have to apologise to the entire community, as I’ve been making you waste your time.

i have been running 127.5 jets all round, so no wonder the bike was running rich. For some reason I wasn’t in my mind, but obviously I was wrong. These were the plastic ones 

i will be ordering today a set of 122,5, and possibly try on the 120s I have.

I am already in touch with Zed1015, and I will still do the plunger thing.

By the way, comparing my old set of carbs with the “new” ones, I realize they have some additional part that looks very much like the restrictors Zed1015 sells for pods. 

is this right? I am using a standard airbox and filter. Please see pics for reference. Upper in pic new, lower old.

again; sorry for the bother and running around like a headless chicken 



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Re: 1981 KZ1000J CARB ISSUES NEED ADVICE

02 Jan 2025 06:56
#907448
Hum, those brass metering jets are very curious.  I've never seen anything like those on an OEM set.  They are almost certainly air restrictors, which will increase how rich the bike runs.  One of our local carb guru's, Clay (asphalt900), mentioned to me that restriction jets like those have been around for quite some time (no disrespect to zed1015, who sells them currently).  There is no slot that I can see in these, which suggests they are pressed in place.  You could remove them and see how the bike runs.  Hopefully, removal won't destroy them.
Ed
Carb O-ring Kits : www.kzrider.com/forum/3-carburetor/61807...-o-ring-kits?start=0

www.kzrider.com/forum/faq-wiki/618026-new-owner-things-to-know

1981 KZ750E2
www.kzrider.com/forum/11-projects/604901...z750e-project-thread
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