Cb350 float needle issue

Discussion in 'Old's Cool' started by usmaan_88, Jun 13, 2013.

  1. usmaan_88

    usmaan_88 n00b

    Joined:
    Jun 13, 2013
    Oddometer:
    2
    Hi all,

    First post on this forum, even though I've been learning a lot over the past few weeks. I bough a 1972 CB350 recently and it's in need of some serious TLC. One of the cylinders was backfiring so, after checking the plugs, I pulled off the carbs to clean them out. Unfortunately, while removing the float valve seat on one of the carbs I think I may have done some damage. The float needle doesn't sit in the seat now that it's been pulled out, it's loose and when I turn it over it just falls out. I'm sure this is a problem seeing as it'll just come off and cause my float level to sky rocket while I'm riding, I was wondering if there's anyway to make the needle fit instead of buying a new needle and seat? And how snugly should the needle fit in the seat anyway? I haven't touched the other carb for fear of doing the same damage.

    Also, my needle jet holder/main jet holders are STUCK, as is the float pin on one of the carbs. Can I use some WD-40 on these parts? Will that help loosen them up a bit?

    Replies much appreciated!

    Usmaan
    #1
  2. ADW

    ADW 'tard bike restos

    Joined:
    May 29, 2009
    Oddometer:
    583
    Location:
    MI
    I'm not familar with the CB350 twin carbs in particular, but any Honda carb (actually I think ANY carb) I've ever dealt with, the float needle SHOULD fall out of the seat. The only thing that holds it in is the tang on the float itself that pushes it against the seat to close it. If you don't have the float installed when you turn the carb over, yeah, the needle will fall out because the float isn't stopping it from falling out.

    Now if you mean the float SEAT falls out, yeah, that's a problem. You must have stripped the threads in the carb body that the seat screws into.

    Below is a photo for terminology's sake. Your parts won't be exactly the same but darn close:

    [​IMG]

    Another photo, this time of just the needle valve and seat. See? Nothing to hold the needle in at all. Bumping up against the brass tab on the float holds it in.

    [​IMG]
    #2
  3. Dolly Sod

    Dolly Sod Red Clay Halo

    Joined:
    Aug 18, 2003
    Oddometer:
    14,070
    Location:
    Richmond, Va


    As ADW said, the needle is supposed to fall out. Held in place by the tang of the float.

    I've used a little punch to remove the float pin, but don't go crazy on it. If a little light tapping doesn't do it, then it's time to let everything soak in carb cleaner.

    You've got a carb kit, correct? You'll be replacing all the old o-rings in these carb, yes? If so, then soaking won't hurt anything. Just make sure you don't soak the slide diaphragms. Keep them in a safe place, and make sure they don't have any pin-holes in them.
    #3
  4. RSRennsport

    RSRennsport Navigator

    Joined:
    Jan 25, 2012
    Oddometer:
    64
    Location:
    Weisse Hoelle / Michigan
    Sadly, the carb's were an issue as are the points.
    You can find OEM rebuild kits online for the carb's if you think you really need them.
    Same for the points. I went with PAMCO.
    Inexpensive, easy to install and you get rid of the condenser.
    Either that that you have a solid bike with that model.
    I have all three, CB/CL/SL.
    #4
  5. usmaan_88

    usmaan_88 n00b

    Joined:
    Jun 13, 2013
    Oddometer:
    2
    Hi guys,

    thanks for clearing this up. Yeah I thought I was being a little paranoid about it. It's the needle that falls out, not the seat so I guess I'm ok. I'm going to get a new carb kit for all the seals, so I suppose soaking the think in carb cleaner wouldn't hurt.

    Thanks again!
    #5