Too much fuel pressure...blows past float valves & floods

Discussion in '3rd & 4th Generation 1990-1997' started by flummerylove, Oct 14, 2011.

  1. flummerylove

    flummerylove New Member

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    Is there a good solution to reduce the pressure? Some sort of inline damper?
     
  2. TOE CUTTER

    TOE CUTTER Mullet Man

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    It is your floats/needle and seat and not the pump to be sure.
     
  3. flummerylove

    flummerylove New Member

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    Yeps. Would that still be the case even after setting float height to 13mm on one carb and successfully lowering fuel level compared to 9mm on other 3 carbs? Does this suggest the float valves are working?
     
  4. TOE CUTTER

    TOE CUTTER Mullet Man

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    Yes, the fuel pump does not have the ability to over power the floats........not even close. Has the bike been sitting for some time? How did we get here?
     
  5. flummerylove

    flummerylove New Member

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    No its been a daily runner. I just finished a pretty major rebuild and have been chasing this one for...too long. In other posts I mentioned that I used float valves and seats from a VT600 but they were too short. The same thing was happening with those but they were new, albeit short. Thats one of the reasons I thought fuel pressure was too high. So I can still alter fuel level, but that doesnt mean the float valves are sealing properly, correct? I jumped the pump and it does stop clicking, I think only after the floats are jecked up to the top of the bowl. I just looked back thru my recent thread. Squirrelman had good info. Check the pics of my fuel level....

    http://vfrworld.com/forums/mechanic...s-closed-flooding-into-cyls-2.html#post332281
     
  6. flummerylove

    flummerylove New Member

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    Ok swapped float valves & seats with new(from a VT600 but should work). Doubled up crush washers to shim up the assy. Still flooding...WTF
     
  7. TOE CUTTER

    TOE CUTTER Mullet Man

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    I think you should install the correct needle and seat. It is a must at this point.
     
  8. flummerylove

    flummerylove New Member

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    Yes will do. Dont get why the old correct assy doesnt work. They dont look very worn. I guess slight wear makes a big diff.
     
  9. ridervfr

    ridervfr Member

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    I second this!~
     
  10. kennybobby

    kennybobby New Member

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    '83-'93 needles are the same

    1st thru 3rd gen are the same length (15.3mm from rubber tip to end of plunger). The '90-93 have a smaller plunger diameter (0.98 vs 1.58 mm) but the earlier versions would still work.

    The VT carbs are mounted at a steeper angle because the Vee is much less than the VFR's 90 degrees, hence the VT has shorter needles to set the float levels.

    i finally got a set of 3rd gen carbs on the bench. Floats are at ~10mm and the fuel level is down into the bowl below the gasket plane--it fills them up right to the lip in the deep end of the pool. The inlet needle jet is marked 2.4. Make sure the spring plungers on the needles do spring back freely.
     
    Last edited: Oct 17, 2011
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