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Carb tuning problems...

Started by Jeepster51, October 21, 2005, 12:54:43 PM

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Jeepster51

I am having problem tweaking my carbs on my 82. I have the modified air box and cleaned each carb with cleaner.

Here is what I know:

These are factory values.
    Main Jet
    [li]Size -- 122.5 front, 127.5 rear[/li]
    [li]Located -- left side near bottom under 10mm bolt[/li]
    [/list]
      Pilot Jet
      [li]Size -- #60[/li]
      [li]Located -- bottom under Flat head bolt[/li]
      [/list]
        Pilot Air Jet
        [li]Size -- #130[/li]
        [li]Located -- Top side in rim[/li]
        [/list]

        I have sync'd the carbs and sealed the YICS. It is running but has no throttle response and once revs up doesn't return to idle in a timely manner.

        From what have read there is a mixture screw also. Is this located left side, bottom, rear? I adjusted that screw 2 1/2 turns out for the front and 4 out rear. The rear carb started leaking fuel from that screw. They were intially all the way in.

        Can anyone tell me where I am going wrong? I don't want to buy different size jets until the stock setup starts running better.

        Superfly

        Carb Synch is essential.? I would start there.? ?Also have you dipped your carbs?? (Assuming that you have) when you dipped the carbs, did you remove the fuel/air mixture screw, it has a spring, washer, and a seal.? make sure you get that seal in there, or you might have some problems....

        Slow return to idle is typically a vacuum leak.? check the YICS box and associated tubing for vacuum leaks.

        I run 135's on the Main air jets.?
        A bad marrage is like dirty carbs... It just makes everything else suck.

        Jeepster51

        The screw (I am not sure its the mixture screw) I removed had a rubber washer and no spring. What are the recomended starting settings?

        Superfly

        the spring provides tension so the screw does not fall out while you are running (it has happened to me.... >:()



        I know it is a 83 kit, but the piolet needle is what I am pointing out.  That is what controlls the fuel/air mixture.  If you look at the pic, you will see a Pilot needle, pilot needle spring,Pilot needle o ring, and a pilot needle washer.

        When I am setting up 82 carbs, I start with 2 1/2 front, 4 1/2 rear.   That has always been a good starting point for me to get the settings correct.

        A bad marrage is like dirty carbs... It just makes everything else suck.

        Jeepster51

        Where is the pilot needle (is this the mixture screw suppose.) located?

        I was messing with the bowl drain screw. That won't tune the carb at all.

        Thanks.

        Superfly

        Lucky's site tells it best.
        http://www.xz550.com/carbindex.html

        Here is the location of the screw (needle) in question....
        http://www.xz550.com/bowl.html
        A bad marrage is like dirty carbs... It just makes everything else suck.

        Lucky

        You might be wasting your time trying to tune your carbs.

        if You only sprayed carb cleaner thru the carbs, that won't do it, you have to strip em' & dip 'em.  some of the passages in the carb are only a few hundreths of an inch wide.  carb cleaner ain't gonna do it.

        --Lucky
        1982/3 XZ550 Touring Vison, Gold on Black

        Night Vision

        Quote from: Superfly on October 21, 2005, 03:44:48 PM
        Lucky's site tells it best.
        http://www.xz550.com/carbindex.html

        Here is the location of the screw (needle) in question....
        http://www.xz550.com/bowl.html



        Jeepster- I am in the process of my first carb strip and dip... when you look at that second link picture (for the mixture screw), you may not see a screw head. It may still have the factory seal over it.?
        if it ain't worth doing it the hard way....
        it ain't worth doing it at all - Man Law
        ;D


        if it ain't broke..... take it apart and find out why


        don't give up.... don't ever give up - Jimmy Valvano

        silicon_toad2000

        Hey Lucky, just for a point of reference, how far above sea level do you live?
        One mans clunker is another mans blank canvas.

        louthepou

        Once, my accelerator pump adjusting rod was... misadjusted. The bike would accelerate, then when I cut the throttle off, it would stay at a high rpm. Scary. A few trial and error adjustments later, the bike was behaving more normally.

        Lou
        Hi, my name is Louis, and I'm a Vision-o-holic

        Lucky

        #10
        about 30 feet..I walk to the docks when i take my boys fishing,
        & fresh lobsta & quahogs are a stones throw away..  ;D
        1982/3 XZ550 Touring Vison, Gold on Black

        silicon_toad2000

        why did I ask that, sorry, brain fart.

        I used to live that close to the beach/water. now its about a half hour drive. I don't miss the rust I can tell you that much.
        One mans clunker is another mans blank canvas.

        Coil Coyle

        Quote from: silicon_toad2000 on October 22, 2005, 06:11:39 PM
        why did I ask that, sorry, brain fart.

        I used to live that close to the beach/water. now its about a half hour drive. I don't miss the rust I can tell you that much.

        Thats Not Rust, it's "PATINA"

        ;D

        coil

        hfarley

        Ok Lucky,
        On your next ROV "ride" you can come down to Jersey and bring me some of that lobstah and some good ole' clam chowder.  LOL! I got a hankering for some good grub and you guys North of me seem to have the receipes down pat. LOL!  ;D (Insert halo here)

        -Heather aka Bat Girl
        Sometimes being insane in an insane world IS being sane

        I don't suffer from insanity....I enjoy every minute of it!

        Superfly

        I have not hankered since I left the east coast.....
        A bad marrage is like dirty carbs... It just makes everything else suck.

        silicon_toad2000

        thats right, I meant to ask superfly how far above sea level he rides, for some point of reference with those 135 air jets.
        One mans clunker is another mans blank canvas.

        Jeepster51

        Thank you All, I see what needs to be tweaked, now.

        I plan on doing the carb dip this winter.

        Thanks again for your help.

        Bryan

        Rick G

        Heather thats pronounced  "clam chowdah"  I have a friend  of 3 decades who is from Maine who instructed on the  correct pronuncation .  Its right up there with "pak the cah "
        Rick G
        Go soothingly on the grease mud, as there in lurks the skid demon
        '82.5 Yamaha XZ550 RJ  Vision,
        '90 Suzuki VX800, 1990 Suzuki DR350.
        '74  XL350   Honda , 77 XL350 Honda, 78 XL350 Honda, '82 XT 200 Yamaha, '67 Yamaha YG1TK, 80cc trail bike