Float heights and how to adjust them

Discussion in 'Carburetor' started by Awk08, Sep 5, 2012.

  1. Awk08

    Awk08 Administrator Staff Member Technician

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    after repeatedly looking for this info every few days, i figured i'd pack it up into an easily found thread........

    the float height in your carb is critical to all jetting ranges and must be set correctly before any jetting or tuning can be done properly.

    this is assuming you've already checked the rubber tip of the float needle, and proven it good, or used the toothpaste trick to clean the float valve. if either is questionable...replace them before proceeding to the adjustment

    check your float height:
    holding the carb on a slight angle, not allowing the floats to depress the spring loaded center needle, just rest against it, measure the float height, from carb body with gasket removed, to top of float like this...........
    CARB.jpg



    to adjust the float height:
    slightly bend the center tab that the float needle hangs on, and remeasure.

    bend it down into the carb for a higher float height measurement, and up for a lower float height measurement,
    (the lower the measurement, the more fuel will be allowed into your fuel bowl, get it exact for correct fuel level)............

    Bowlparts.jpg

    carb6_08010txta.jpg




    here's the float height's of the most popular carbs run on our blasters.......

    26mm vm mikuni - 20-21.5 mm (stock carb)
    28mm vm mikuni - 22mm
    30mm mikuni - 23-25mm
    32/34/36 tm mikuni - 18mm

    30mm oko - 19-20MM.

    keihin carbs -

    [​IMG]



    also see these threads for more good float info:

    leaky float valve
    http://www.blasterforum.com/threads/easy-and-almost-free-way-to-stop-leaky-carbs.33335/


    float video
    http://www.blasterforum.com/threads/carburetor-overflow-problem-vid.55600/
     
  2. scotj77

    scotj77 Member

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    good stuff awk. I wish this site was like google. when people started typing in key words threads start popping up according to what they type. lol I don't mind helping people out but answering the same question a few times in one week get's old
     
  3. Herpderplol

    Herpderplol BRRAAAAAAAAAPP

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    That is good advice, I found this site after searching on google about some carb work, and boy am i glad i found it I:II:II:II:I
     
  4. Blaaster

    Blaaster Moderator Staff Member Technician

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    Thats some good oil there Awk, little bit of green rewarded.
     
  5. BlasterBenny

    BlasterBenny New Member

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    Great thread, it worked for mine pissing carb!I:I

    Cheers,
    Benny.
     
  6. mastuhblastuh

    mastuhblastuh Member

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    perfect. just perfect!!!
     
  7. Yert

    Yert Supporting Member Forum Supporter

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    Very helpful thank you.
     
  8. melanie

    melanie New Member

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    I'm having some issues with my carb and came across this post.... when my bike is off and the gas is on I'm leaking fuel out of the drain tube. Could that be a float adjustment issue or something else?

     
  9. Markblaster

    Markblaster Custom blaster

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    Needs adjusted. Check it.
     
  10. speedyslyder

    speedyslyder 2 STROKES RULE Technician Forum Supporter

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    ok i will play along read what i wrote uhh few days ago's:D
    both of my replys..and watch the full videos clips..........o_O
    lets look at all possibilties
    float level/or a hole in the floats/floats getting hung up somehow
    needle seat worn out or dirty
    drain screw is not seating properly as in it will leak if it is loose/as in you can drain the bowl from that screw:)
    1 more the float bowl gasket is leaking
    whatever makes more sense to the individual it is written all over the web
    http://www.blasterforum.com/threads/carb-leaking.66579/
     
    Last edited: Aug 9, 2017
  11. Awk08

    Awk08 Administrator Staff Member Technician

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    if your float height is correct and it's still pissing out fuel, it's gotta be the float valve.... dirty or torn.
    if cleaning it doesn't help, replace it
    http://www.blasterforum.com/threads/easy-and-almost-free-way-to-stop-leaky-carbs.33335/
     
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  12. melanie

    melanie New Member

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    Jeeze. I actually did read this thread yesterday. And I have been thru all of this. My floats do not have holes, I've float tested them more than once. New needle, drain screw is not loose, and brand new gasket. But thanks for the info. Again apparently, my bad.

     
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  13. Awk08

    Awk08 Administrator Staff Member Technician

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    Use the Q-tip n toothpaste method to clean the needle seat. If it gets gummed up the needle won't seal, new or not.
     
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  14. speedyslyder

    speedyslyder 2 STROKES RULE Technician Forum Supporter

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    okay i forget something's haha:D
    at least we got some pro advice/\/\:cool:
     
  15. melanie

    melanie New Member

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    Thanks. Is putting an idle screw kit in necessary for this m-effer to run right?

     
  16. Awk08

    Awk08 Administrator Staff Member Technician

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    if it has a regular carb cap and the TORS brick on top removed, then yes it needs an idle screw drilled/tapped in the side.
    if TORS still present, the idle screw is accessed from under the tank, remove seat, lift rubber flap and look under there beside the coil, big straight blade screw.
     
  17. Markblaster

    Markblaster Custom blaster

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  18. melanie

    melanie New Member

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    Oh okay thanks. I did a TORS delete last week but only the electrical aspect of it. So I will look at the cap today. Hopefully that will fix my issue

     
  19. melanie

    melanie New Member

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    Thanks for all ur help guys. My bike is finally idling and no longer dumping fuel. I think I'm set with the 280 jet, just took it for a ride, although now my throttle is sticking and it wasn't before
     
  20. Yert

    Yert Supporting Member Forum Supporter

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    The slide that sits on the top of the carb is sticking. Pop it off, check the spring, check the slide surface, and take a peek down the hole it was it. Make sure everything is clean and clear of debris. Also note the slide will go back together in 2 positions, 1 of which will keep throttle at 100% and obviously that's not the one you want.
     

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