1. Some members were not receiving emails sent from XJbikes.com. For example: "Forgot your password?" function to reset your password would not send email to some members. I believe this has been resolved now. Please use "Contact Us" form (see page footer link) if you still have email issues. SnoSheriff

    Hello Guest. You have limited privileges and you can't "SEARCH" the forums. Please "Log In" or "Sign Up" for additional functionality. Click HERE to proceed.

setting fuel level

Discussion in 'XJ Technical Chat' started by moonfriedpotatoes, Jul 19, 2010.

  1. moonfriedpotatoes

    moonfriedpotatoes Member

    Messages:
    239
    Likes Received:
    1
    Trophy Points:
    16
    Location:
    Montana
    just started to check my fuel level using the "clear tube method"

    is there a link to a nice, illustrated how-to of this procedure? i tried searching for a bit but no detailed instructions.

    so far i've gleaned that you attach clear tubes to the drain ports on the bowls, then measure the amount of gas in them using the joint between bowl and carb body as a reference. the level should be 3mm +/- 1mm... below the carb joint?

    I attached tubes and opened all four drain ports, and the fuel levels are all over the place, despite the proper dry setting. started to adjust #1 (way too low) by bending the float tang, but it's not making much of a difference, and I've pushed the tang a long way away from the carb body.

    the float itself is oriented with the flat surface towards the ground when carbs are held right side up.

    bending the tang away from the carb body makes fuel level increase, while being the tang towards the body makes fuel level decrease, right?

    I'm going to keep fiddling and see how it goes.
     
  2. bigfitz52

    bigfitz52 Well-Known Member Premium Member

    Messages:
    21,283
    Likes Received:
    418
    Trophy Points:
    83
    Location:
    Rural SE Michigan 60 miles N of Motown
    Which is why we check them "wet."

    Do one carb at a time, hold the hose up next to the side of the carb (as close as you can on the inner carbs) then open the drain screw.

    If you flail all about with the hoses, they can end up with too much fuel in them and not enough pressure differential going for them to push it back into the bowl.

    The procedure is outlined in both the factory and aftermarket service manuals and discussed to death here, so the lack of a how-to isn't surprising.

    Not being 100% sure that Mikunis and Hitachis are exactly alike, I'm not giving "which way to bend" advice. I can tell you that you shouldn't have to bend the tang very far; if you do there is most likely a different issue with the needle valve.
     
  3. schmuckaholic

    schmuckaholic Well-Known Member

    Messages:
    2,260
    Likes Received:
    42
    Trophy Points:
    48
    Location:
    California
    There is now.

    Chacal had one, but I rewrote it and put in lots of purdy pictures.
     
  4. bigfitz52

    bigfitz52 Well-Known Member Premium Member

    Messages:
    21,283
    Likes Received:
    418
    Trophy Points:
    83
    Location:
    Rural SE Michigan 60 miles N of Motown
    Very nice. Thanks.
     
  5. moonfriedpotatoes

    moonfriedpotatoes Member

    Messages:
    239
    Likes Received:
    1
    Trophy Points:
    16
    Location:
    Montana
    I'm not a moderator or anything, but that should be in the archives somewhere. thanks!!

    how can i check for needle valve/seat issues? I bent the tang a long way and it didn't make much difference.
     
  6. Erman

    Erman Member

    Messages:
    336
    Likes Received:
    0
    Trophy Points:
    16
    Location:
    Oslo, Norway
    I did the following when installing the Float Seat and Needle Valve:

    Blow through the "backside" of the Float Seat while pushing the Needle Valve in and out. You should notice if there are any leaks, which would indicate if the valve/seat was worn...
     
  7. moonfriedpotatoes

    moonfriedpotatoes Member

    Messages:
    239
    Likes Received:
    1
    Trophy Points:
    16
    Location:
    Montana
    I'll do that erman, thx.

    thing is, all my levels are LOW. I though worn needle valves or seats resulted in leaks and HIGH fuel levels... what about the needle valve/seat would result in a low fuel level?
     
  8. bigfitz52

    bigfitz52 Well-Known Member Premium Member

    Messages:
    21,283
    Likes Received:
    418
    Trophy Points:
    83
    Location:
    Rural SE Michigan 60 miles N of Motown
    Did you install new needles that are substantially longer than the originals, requiring a rather drastic adjustment to bring them in? Look at the article schmuck posted. If not, then I would say something's binding or assembled wrong.

    You are working on the rack off the bike, mounted perfectly level in all horizontal planes, and holding the tube next to the center of the side of the carb, right?
     
  9. RickCoMatic

    RickCoMatic Well-Known Member

    Messages:
    13,843
    Likes Received:
    66
    Trophy Points:
    48
    Location:
    Massachusetts, Billerica
    I've had to change the Float Levels on Carbs sent-in where the Float Pin's in the Carbs were of the SOLID Type and the Kits have Float Pins of the SPRING LOADED Type.

    I don't remember the Kit Brand.
     
  10. snowwy66

    snowwy66 Member

    Messages:
    892
    Likes Received:
    2
    Trophy Points:
    16
    Location:
    Salt Lake City, Utah
    so how do you use the 3mm float level on a V twin motor? cuz one carb sits at a 90 degree angle.

    the float height spec calls for 17.5 mm. without the gasktet.
     
  11. moonfriedpotatoes

    moonfriedpotatoes Member

    Messages:
    239
    Likes Received:
    1
    Trophy Points:
    16
    Location:
    Montana
    @ fitz ... everything is stock. floats are the right way up. 1+4 are really low (1/2"). what could be binding?

    Rack is off bike on a bench. I've measured @ dead level and tilted forwards like the manual says. still super low. might give em a light whack with a hammer to see if it frees up the needle valve, but other than that, where could things be binding?
     
  12. RickCoMatic

    RickCoMatic Well-Known Member

    Messages:
    13,843
    Likes Received:
    66
    Trophy Points:
    48
    Location:
    Massachusetts, Billerica
    If the Bike "Sat" ... the Float Hinge can almost seize.

    Run a Twist Drill into the Float Hinge Cylinder and clean-out any foreign matter that might be hindering movement.

    If the Float Hinge Pin has deteriorated, ... replace the Hinge Pin with the Shaft of a Pop Rivet.
    One Pop Rivet size is a Perfect fit.
     
  13. moonfriedpotatoes

    moonfriedpotatoes Member

    Messages:
    239
    Likes Received:
    1
    Trophy Points:
    16
    Location:
    Montana
    thanks rick. all good there. I'm going to create another topic with all my issues condensed for further reading. spent soome time with my mechanic today chewing the fat.
     
  14. snowwy66

    snowwy66 Member

    Messages:
    892
    Likes Received:
    2
    Trophy Points:
    16
    Location:
    Salt Lake City, Utah
    gas over time turns to varnish which can act like sticky glue causing the needles to stick.

    also, check those needles that the float hinges on. might be bent.
     
  15. wizard

    wizard Active Member

    Messages:
    5,282
    Likes Received:
    26
    Trophy Points:
    38
    Location:
    DEVON ENGLAND
    check those needles that the float hinges on. might be bent.
    [snowwy66 quote]

    can I have some of what you are on?
     
  16. snowwy66

    snowwy66 Member

    Messages:
    892
    Likes Received:
    2
    Trophy Points:
    16
    Location:
    Salt Lake City, Utah
    i'm sorry that you've never seen it happen. but you'd be amazed how some people try to adjust there floats. i've seen bent float hinges couple of times.

    so what is it you'd like me to be on?
     
  17. moonfriedpotatoes

    moonfriedpotatoes Member

    Messages:
    239
    Likes Received:
    1
    Trophy Points:
    16
    Location:
    Montana
    ouch. you guys can have what im on, it's AWESOME!!! hard to type tho... =D

    i got ye olde floats figgered out thanks for all the help
     
  18. FinnogAngela

    FinnogAngela Member

    Messages:
    205
    Likes Received:
    1
    Trophy Points:
    16
    Location:
    Copenhagen, Denmark
    What did you do that made it right?
     
  19. moonfriedpotatoes

    moonfriedpotatoes Member

    Messages:
    239
    Likes Received:
    1
    Trophy Points:
    16
    Location:
    Montana
    i set the fuel levels by bending the tang; didn't realize how big a difference a small adjustment made.
     
  20. schmuckaholic

    schmuckaholic Well-Known Member

    Messages:
    2,260
    Likes Received:
    42
    Trophy Points:
    48
    Location:
    California
    I did make note of that, if you'll recall. Bottom of page 6.

    "Fractions of a millimeter count; a minute adjustment can cause the fuel level to vary greatly."

    That's being changed... instead of "minute", it'll be "very, very small" adjustments. Darn that pesky english language -- the meanings and pronunciation of words change depending on context.

    Oh, here's another question for the general audience: the picture of the floats on page 4, where I thoughtfully colored the tang arm in an orange hue. Is that obvious enough, or would a nice neon color work better? (It'd be great if we could get it to flash "EAT... AT... JOE'S...".)
     
  21. moonfriedpotatoes

    moonfriedpotatoes Member

    Messages:
    239
    Likes Received:
    1
    Trophy Points:
    16
    Location:
    Montana
    you should make it blink... or maybe paint it with a rainbow
     
  22. padre

    padre Member

    Messages:
    233
    Likes Received:
    0
    Trophy Points:
    16
    Location:
    Lawton, Oklahoma
    jeez-louise dosn't anyone know how to pre set the float level and float drop dry before putting them together?
     
  23. FinnogAngela

    FinnogAngela Member

    Messages:
    205
    Likes Received:
    1
    Trophy Points:
    16
    Location:
    Copenhagen, Denmark
    A lot of posts and discussions about dry float height settings indicate:

    1: The matter is pretty complicated, as it isn´t always easy to find the right specs for float height

    -1b: Even if you find a manual spec, cleartube check can prove that wrong (reasons for this can be different/aging float valves, difference in the floats absorbtion (yes, they do) of fuel, different density of fuel (leaded/unleaded/ethanol etc.)

    -1C: The manual could simply be wrong (The XJ700-X 17.5mm is an impossibility, and my 700N´s 16mm was about 2mm´s off..)

    2: Even if you dry set all float heights dead even, tube test might show uneven fuel levels.

    No easy way round setting the right fuel level, which is what we´re aiming for, I´m afraid.
     

Share This Page