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Xj550 seca float height?

Discussion in 'XJ Technical Chat' started by ecologito, Feb 25, 2015.

  1. ecologito

    ecologito Well-Known Member

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    Hi,

    I am gonna set the float level on the 550 seca and I am curious if somebody knows how to measure the floats and what height before closing and trying the first wet set.

    I have two floats at one height and noticed two at different heights. I am just curious about the starting point before the wet set
     
  2. BleedingOxide

    BleedingOxide Member

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    My floats sit 19.8mm above gasket height at their highest point, so mebbe start there.
    Wet set 2mm below the lip (+/-1mm)
    I found that a 6mm clear plastic tube has a 2mm Meniscus. very convenient.
     
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  3. hogfiddles

    hogfiddles XJ-Wizard, Host-Central NY Carb Clinic Moderator Premium Member

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    Yamaha used to post that the 550 carbs were to be initally set at 21.5mm. Now they don't post a number, just say to set fuel height.

    Mikuni BS28 (All 550 except 550L)
    2mm +/- 1mm (.08" +/- .039")

    Mikuni BS32 (all 550L)
    3mm +/- 1mm (.12" +/- .04")

    I still set the 550 carbs at 21.5mm for initial setting.

    Dave Fox
     
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  4. ecologito

    ecologito Well-Known Member

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    Thank you for the info,

    I have been able to easily find info on the wet set height but I guess the dry set (starting point) is becoming more of a guesstimate since you have to wet set anyways.
     
  5. ecologito

    ecologito Well-Known Member

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    I just set them at 21.5 mm and they all were really low (about 4 mm below that mark). Now it will be a matter of looking at the wet set and see what they do.
     
  6. hogfiddles

    hogfiddles XJ-Wizard, Host-Central NY Carb Clinic Moderator Premium Member

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    Do you mean they were low before you set them to 21.5mm, or "after you set them at 21.5mm, and then did a wet check, they fuel level was too low"?

    I read that first, and made a few comments to others, then just re-read it and now translated it differently. So, I'm checking with you.

    Now, I'm assuming you mean that "while the bowls were still open and upside down, the floats were too low and were not reaching the 21.5mm mark yet" (cuz you know, if the floats are to low if the carbs are upside down, then theyre really too HIGH, and if they are too high when the carbs are upside down, then they are really too LOW.

    Just checking specifically what you mean.......LOL

    Dave F
     
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  7. ecologito

    ecologito Well-Known Member

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    When I checked the floats as they came out of the bike they were below 21.5 mm my guess between 17 and 18 mm. I have set them all to 21.5mm so far. I have not done a wet set yet as squirrels chewed through my gas bottle when it sat out on the driveway.

    Not sure why a squirrel would want to chew on a red plastic container that smells like gas... little jerks!
     
  8. hogfiddles

    hogfiddles XJ-Wizard, Host-Central NY Carb Clinic Moderator Premium Member

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    Ok..... that's just what I was wondering!! I read the post the other day, and understood it totally differently. THEN......last night re-read it and had a different take on it, that's why I thought I'd better ask. That makes me feel better.

    Thanks, Eco.
     
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  9. Toomanybikes

    Toomanybikes Well-Known Member

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    Ok Dave
    To what point do you measure to
    A -metal tang
    B -plastic body
     

    Attached Files:

  10. hogfiddles

    hogfiddles XJ-Wizard, Host-Central NY Carb Clinic Moderator Premium Member

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    I measure those at point B
     
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  11. XJ550H

    XJ550H Well-Known Member Premium Member

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    if you do wet set on one carb before reassembling the rack you can get a setting with out all that gas in the other carbs
    then set the floats on the other carbs to that setting as a starting height. eliminates a step.
     
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  12. 1jeffs

    1jeffs New Member

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    Hi Dave, how do I know if I have the 28 or the 32. It’s an 82 maxim 550. Thanks
     
  13. hogfiddles

    hogfiddles XJ-Wizard, Host-Central NY Carb Clinic Moderator Premium Member

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    The 550L was 1984. Yours is 1982, so it’s not a L.

    also, as I understand it to be, and find it to be true..... the 550 racks are pretty finicky. The fade setting of 21.5 seems to be to just get you in the neighborhood of where the wet set will be, unlike the 650/750 which is usually pretty darn close. The mixture screws also tend to have to be adjusted farther either way on the 550.

    ALSO, most of the time it’s not worth the hassle of re-installing the heat shield either, cuz You gotta take it back off to remove a bowl. If you take that off, now you’ve just disrupted your sync, cuz the shield is held on by the same bolts that hold the lower rail in place.

    dfox
     
  14. 1jeffs

    1jeffs New Member

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    Thanks for the info. So looks like I will be using the 2mm +\- spec. And I have a top bracket on my carbs so I was able to remove the heat shield and reinstall the lower bracket without moving the carbs at all. ( I hope).
     
  15. hogfiddles

    hogfiddles XJ-Wizard, Host-Central NY Carb Clinic Moderator Premium Member

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    that’s right.... you hope—-
     
  16. 1jeffs

    1jeffs New Member

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    Will any size tubing work? I read 6mm ID someplace but that won’t fit in the holes. I have some that fits great in the holes but it’s small ID. With the hose I have I am level with top edge of bowl on all 4 carbs with the carb top covers level. What are your thoughts other than the fact fuel is too high? Thank you
     
  17. XJ550H

    XJ550H Well-Known Member Premium Member

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    you have to buy a nipple from xj4ever to fit into the hole. or get a vacuum fitting from autoparts store and taper it to fit.
    hose does not go inside hole
     
  18. Huntchuks

    Huntchuks Well-Known Member

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    This is what I use on the Hitachi carbs, may be different sizing for you. Clamp the larger section to the bowl drain hole, flex the smaller hose easily to any shape to get a good reading. I was tired of fighting with the large diameter tubing.
    20200420_181006.jpg
     
  19. XJ550H

    XJ550H Well-Known Member Premium Member

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    he has no nipples
    upload_2020-4-20_18-39-26.png

    we use this handy contraption – since the Mikunis have Innies instead of Outies (like the Hitachis), we can’t just plug in a hose. www.maxim-x.com shows how it’s made.
    mikbowl.PNG


    http://www.maxim-x.com/fuel_level_gauge.html


    Mikuni BS28 (all XJ550 except 1984 XJ550L): -Fuel level measured via the clear-tube gauge: 2mm +/- 1mm (.08 +/- .039 inches) -Float height: 21.5 +/- 1.0mm
     
    Last edited: Apr 20, 2020
  20. hogfiddles

    hogfiddles XJ-Wizard, Host-Central NY Carb Clinic Moderator Premium Member

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    Oh man, for a second there I was thinking MattiThundrr was back
     
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