Need help leaning out fuel/air mixture

fatcat70
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Need help leaning out fuel/air mixture

26 Sep 2016 17:47

I just bought a 1980 kz550 ltd a week ago. I cleaned the carbs and got it running. However it seems to be running rich. There are dry carbon deposits on The spark plugs and black smoke coming out of the exhaust pipes as well as a raw fuel smell. My question is how do I lean out the fuel/air mixture?

1980 kz550 LTD

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TexasKZ
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Re: Need help leaning out fuel/air mixture

26 Sep 2016 18:34

#743656

Did you confirm proper fuel level using the clear tube method? If not, that is the place to start.

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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fatcat70
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Re: Need help leaning out fuel/air mixture

26 Sep 2016 19:26

#743658

Eh... I kind of half assed the clear tube test. I couldn't find tubing that fit the overflow nipples that well so I've been guessing on the float heights (over several itterations) based on how much gas was spilling out.

1980 kz550 LTD

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SWest
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Re: Need help leaning out fuel/air mixture

26 Sep 2016 19:55

#743661

They have to be at the correct height and even.
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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fatcat70
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Re: Need help leaning out fuel/air mixture

26 Sep 2016 20:00

#743662

Do I need to buy special tubes for it or should I put more effort into Jerry rigging tubes to fit the nipples tightly ?

1980 kz550 LTD

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SWest
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Re: Need help leaning out fuel/air mixture

26 Sep 2016 20:16

#743664

Clear 1/4" tubing heated to fit tight should do it.
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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kaw-a-holic
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Re: Need help leaning out fuel/air mixture

26 Sep 2016 21:42

#743675

fatcat70 wrote: Do I need to buy special tubes for it or should I put more effort into Jerry rigging tubes to fit the nipples tightly ?

Autozone has tubing for lawn mowers that will fit. Napa has tubing that will fit. You could even go to Ace hardware. It doesn't have to be fuel rated its only going to be used for a short while to get the levels right. This is a very important step to carb tuning.

I use one of these, worth every penny: www.z1enterprises.com/product/ZSM01-208

Jon
1977 KZ1000a1
Mesa, AZ
Phoenix Fighter Project

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650ed
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Re: Need help leaning out fuel/air mixture

27 Sep 2016 04:44

#743683

kaw-a-holic wrote:

fatcat70 wrote: Do I need to buy special tubes for it or should I put more effort into Jerry rigging tubes to fit the nipples tightly ?

.............This is a very important step to carb tuning. I use one of these, worth every penny: www.z1enterprises.com/product/ZSM01-208

That really is a bargain! Before those were offered for sale I made a very similar tool for my carbs, and it cost me more to make one than than Z1E is asking for one already made. Ed

1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)

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fatcat70
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Re: Need help leaning out fuel/air mixture

27 Sep 2016 04:50

#743686

Is there a rule of thumb for how much to bend the tang? I.E. a. +/- 1 deg bend in the tang = +/- 1mm change in fuel level?

1980 kz550 LTD

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undiablo
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Re: Need help leaning out fuel/air mixture

27 Sep 2016 05:12

#743687

How would you measure 1º at the small tang?

Kawasaki KZ 750/4 LTD 1981
Kawasaki KLR 650 2011
Argentina - Buenos Aires

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SWest
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Re: Need help leaning out fuel/air mixture

27 Sep 2016 06:47 - 27 Sep 2016 06:49

#743692

The tang should be almost level. If on too much an angle the needle will be cocked sideways and leak. You bend the float arms then the tang is for FINE adjustments.
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

Last edit: 27 Sep 2016 06:49 by SWest.

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fatcat70
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Re: Need help leaning out fuel/air mixture

28 Sep 2016 18:15 - 28 Sep 2016 18:18

#743853

So I'm currently in the process of the clear tube test. Numbering from left to right... Carbs 1 and 2 are leaking gas out of the little holes in the bottom of throat (see picture) but the fuel in those clear tubes isn't quite to the level of the gasket. Does this mean there's still too much fuel in the bowl?

1980 kz550 LTD

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Last edit: 28 Sep 2016 18:18 by fatcat70.

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