Carb issues 89 Sportster

Discussion in 'Sportster Models' started by pike1612, May 14, 2010.

  1. pike1612

    pike1612 Member

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    I have an intermittent fuel overflow problem.I have installed an inline fuel filter and checked the floats and cleaned the carb.Sometimes i can switch the petcock to reserve and it eliminates the problem? what gives.What leaves me clueless is that its intermittent.
     
  2. glider

    glider Veteran Member

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    You may have a problem with the fuel strainer in the tank on the petcock.
     
  3. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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    The other thing is you may have debris that is sometimes fouling up the needle/seat area, as it is the only thing preventing gravity fuel flow from getting past carb and fill the engine cylinders/crankcase with gas. Do you have a vacuum petcock...that diaphragm may not be shutting off the fuel properly when engine is off...and so the flooding cycle begins.
     
  4. pike1612

    pike1612 Member

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    Yes,it is shutting off properly-i had to alternate "off and on" to drive it home yesterday.I would allow the bowl to fill and then shut off the fuel to prevent the overflow.
     
  5. glider

    glider Veteran Member

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    From what you say here "overflow" there's probably some debris in the needle and seat area keeping the inlet valve from closing causing the problem. You'll have to open the float bown and remove the float and needle to let some fuel pass through the inlet valve to flush it out. Some carb cleaner in an aerosol can then to clean the other parts.
     
  6. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

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    The float needle has a rubber coating on the tip after a number of years use the rubber coating can harden and fail to seal properly
    So if you have cleaned the float needle and seat and it still leaks it may need a new float needle

    Brian
     
  7. pike1612

    pike1612 Member

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    I will investigate further. Thanx.
     
  8. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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    Pike1612, yes definitely have a grooved viton needle, or seat has debris/varnish preventing that needle from pinching off the fuel when the float level is correct...flooding the works. Rebuild kit is $36 and should be gotten from the dealer BEFORE disassembly in case they have to order it. Save yourself a lot of trips and a single disassembly/reassembly and your done!

    Also give you a chance to set up well lit, clean area (plenty of small parts easily lost), source of compressed air (to blow out tiny passages) and carb cleaner or brakleen (non-chlorinated) which is milder and won't attack rubber parts for clean up.
     
  9. pike1612

    pike1612 Member

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    My float level was measuring 21.5mm-the manual states 18.5mm.i adjusted the tang accordingly.is that enough to cause flood issues? the float needle and seat i inspected thoroughly-the rubber tip was hard yet somewhat flexible with no grooves or indentations on the needle-and the seat was fine as well-jets are clean as a whistle and bouyancy tested the floats in water-no leaks.Sooo-can i go with the incorrect float height? man,i really dont wanna reinstall and take this dude apart AGAIN LOL!
     
  10. BUBBIE

    BUBBIE Well-Known Member

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    Can't tell you what My setting is on the float, But it is real close to Over Flow..

    I can smell gas every once and a while But I like my carbs set right on the Edge of Too Much.. Just My Way. Probably would run fine at the lesser amount of gas height in the bowl....

    Seems My 2006 XLHR runs fine "at the edge" as set and I will leave it there..

    I always Turn off the pet-cox, between rides, at the tank just for safety.. whether valve is vacuum or manual.

    signed....BUBBIE