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Monobloc 389 Float Bowl Help

Discussion in 'Other Norton Motorcycles' started by AgentX, Aug 15, 2018.

  1. AgentX

    AgentX

    Joined:
    Jul 2, 2015
    Is this range of motion for the float normal? Lacking a frame of reference (first bike with Amals) it seems rather limited to me. The tickler can barely reach the float.




    If it's not normal, what could be the issue? Incorrect float? Incorrect needle?

    Thanks!
     
  2. Beach

    Beach VIP MEMBER

    Joined:
    Aug 27, 2013
    Correct float. Might want to replace float needle with a brass one with vinton tip, check float level and see if you need the washer under float jet. The tickler is supposed to push down on float at highest level to flood float bowl for easy starting.
     
  3. texasSlick

    texasSlick VIP MEMBER

    Joined:
    Jan 2, 2013
    Proper fuel level is at the "pip" near the center of the bowl cap. Place a 12 to 16 inch length of 1/8 " ID clear tubing over the idle jet, curve tubing into a manometer to see fuel level when the cap is in place. Add (increase fuel level) or remove (decrease fuel level) washers under the needle seat to adjust level.

    I agree with Beach .... The float is correct, but the needle and/or seat may be incorrect.

    Slick
     
  4. AgentX

    AgentX

    Joined:
    Jul 2, 2015
    Thanks both for the info...will check the fuel level.

    The tickler seemed to stop functioning correctly; it won't seep gas out the top when depressed. When I saw how the tickler barely touched the float, I figured maybe it has a problem.
     
  5. Bodger

    Bodger VIP MEMBER

    Joined:
    May 9, 2017
    Sometimes when the gas in the float chamber evaporates, the residue on the needle jet can glue it on to the seat. I think this is a modern gas phenomena. When this happens pushing the float down with the tickler doesn't have any effect. The next time pushing the tickler down doesn't have any effect take the float cover off and see if the needle is stuck in the closed position.
     
  6. AgentX

    AgentX

    Joined:
    Jul 2, 2015
    Thanks again, guys. I had a hard time getting a good seal on the tubing around the pilot jet, but once I got it somewhat right, the level seemed a bit low. Waiting on a brass needle now.
     
  7. AgentX

    AgentX

    Joined:
    Jul 2, 2015
    Just to follow up, the brass needle seems to allow more movement, and the tickler gets a nice push on the float. Odd, because it seems just about the same length.
     
  8. texasSlick

    texasSlick VIP MEMBER

    Joined:
    Jan 2, 2013
    The seat orifice may have something to do with it. I think (think means I am not certain) the same needle was used with a 0.100 orifice seat and also with a 0.125 orifice seat. Naturally, the needle will penetrate deeper into the larger orifice.

    Slick
     
  9. AgentX

    AgentX

    Joined:
    Jul 2, 2015
    Ah, so that's what the .125 stamped on the seat hex flats refers to. Very good to know.

    (Luckily, I am way too mature to giggle at all at your last sentence.)

    Thx!