Needle Height

weales
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Needle Height

13 Nov 2015 22:16

Rebuilding my '78 Z1-R carbs and would like to know what position is recommended for the needles - mine were set to the second slot from the bottom of the needle ie 2nd highest setting.

Current Project
1968 Norton P11A Desert Sled
Other bike (and daily ride)
2004 Yamaha FZR 600
Previous Bikes
78 Z1-R (resto)
91 Zephyr 750
73 Mach IV (Resto)
78 Z1-R
78 Z1-R (stolen)
76 Z900
76 Z650
73 Mach IV
72 Mach III

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Patton
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Re: Needle Height

13 Nov 2015 23:25

#698581

Would use the stock middle clip position.

Good Fortune!

1973 Z1
KZ900 LTD

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zed1015
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Re: Needle Height

14 Nov 2015 01:18

#698583

Middle is stock as Patton states but why are they lifted a notch in the first place ?
Are there any mods , non std exhaust or stacks fitted or has it been altered for altitude reasons ?
Did it run fine before the strip ?
If any of the above applies and it ran fine there is no reason to change it just for the sake of it.

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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weales
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Re: Needle Height

14 Nov 2015 02:05

#698585

Engine has been rebuilt to standard - (1st O'size) and has not been run since.
I'll be fitting std airbox, air cleaner and silencer and a Delkevic 4:1 full stainless exhaust.
So will use middle needle height - thanks.
Not sure what main jets to use - any suggestions for this setup please?

Current Project
1968 Norton P11A Desert Sled
Other bike (and daily ride)
2004 Yamaha FZR 600
Previous Bikes
78 Z1-R (resto)
91 Zephyr 750
73 Mach IV (Resto)
78 Z1-R
78 Z1-R (stolen)
76 Z900
76 Z650
73 Mach IV
72 Mach III

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Nessism
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Re: Needle Height

14 Nov 2015 03:06

#698588

Since you have an exhaust I'd leave the clip where it is. Just a smig richer through the midrange.

What kind of air filter are you going to use? K&N? Paper?

I'd leave the pilot alone and bump the mains a point or two, Sort of depends on the filter and how much exhaust restriction you are going to run.

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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SWest
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10 22 2014
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Re: Needle Height

14 Nov 2015 04:27

#698592

Sound advice.

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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zed1015
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Re: Needle Height

14 Nov 2015 04:58 - 14 Nov 2015 04:59

#698597

STD mains were either 107.5 or 112.5 depending on country.
My 78 UK Z1R D1 had 112.5's from new but the US ones seem to mostly be 107.5's probably due to all that emissions crap you had on them.
I'd start with 115.s if it's just a pipe change but 112.5's will probably be enough.
Better to be slightly rich rather than weak.

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

Last edit: 14 Nov 2015 04:59 by zed1015.

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Rockranch
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Re: Needle Height

14 Nov 2015 06:37

#698612

All carb adjustments and settings (low, mid and high range) collectively depend on various factors and setups, including climate and altitude...as well as road tests. It's good you are smart enough to research it and not just make changes with the potential to harm your engine in the long run. Best of luck................Mike

(2)-1976 KZ900B-LTD's
1-all stock low mileage...
1 modified
1977 KZ1000 (awaiting resurrection!)

...and an old school Honda CB750 Chopper is next on my bucket list!

Oh...and a Pocket Rocket lol!!!

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Rockranch
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Re: Needle Height

14 Nov 2015 07:10

#698614

P.S. Youtube is a great source to search for mechanical and tuning videos of various types. I've also seen several carb videos in browsing around youtube that may interest you as well. A bit of searching may just find you the info you seek. GL..................Mike

(2)-1976 KZ900B-LTD's
1-all stock low mileage...
1 modified
1977 KZ1000 (awaiting resurrection!)

...and an old school Honda CB750 Chopper is next on my bucket list!

Oh...and a Pocket Rocket lol!!!

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weales
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Re: Needle Height

14 Nov 2015 16:59

#698680

Ok - I have a set of 113 main jets so will try these.
Air filter will be standard paper element.
Will go with the needle raised one notch from normal to start with.
Then will make any adjustments when/if necessary once the engine is running.
Thanks to all for hints/tips

Current Project
1968 Norton P11A Desert Sled
Other bike (and daily ride)
2004 Yamaha FZR 600
Previous Bikes
78 Z1-R (resto)
91 Zephyr 750
73 Mach IV (Resto)
78 Z1-R
78 Z1-R (stolen)
76 Z900
76 Z650
73 Mach IV
72 Mach III

Please Log in or Create an account to join the conversation.