Jet Stuck in Carb

Discussion in 'Airheads' started by LanceR75, Oct 31, 2012.

  1. LanceR75

    LanceR75 Adventurer

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    Man, this left carb is grungy! I've gotten it torn apart but one of the jets is stuck and I've half stripped the flat head screw trying to get it out. Should I try soaking it in something or will I have to drill it out?

    Cheers!
    #1
  2. oldroadie

    oldroadie Two wheel addict

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    I've had pretty good success on other stuck fasteners with a 50-50 mix of acetone and ATF and soaking for a good while.
    #2
  3. Airhead Wrangler

    Airhead Wrangler Long timer

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    that or try some heat on it.
    #3
  4. Cordless

    Cordless Two Wheel Addict

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    Use an impact driver instead of screwdriver--even if all you do is twist the impact drive instead of striking it. If just twisting it doesn't free it, strike it gently with a heavy hammer.

    I have had good luck with Kroil for loosening.
    #4
  5. LanceR75

    LanceR75 Adventurer

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    I actually did try tapping the outer housing to loosen it and successfully bent the housing so, now I get to fix that as well.
    #5
  6. JonnyCash

    JonnyCash turd polisher

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    I'd try gentle heat. A heat gun, or boil it for a bit. Aluminum expands quite a bit when heated, more than most anything else, which will loosen things up. Be patient, and don't lose your cool.
    #6
  7. bmwhacker

    bmwhacker Still on 3 wheels

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    +1 on the heat gun.
    I use one to warm up pistons...."sticky" wrist pins slide right in / out with a little expansion of the aluminum.
    #7
  8. mfp4073

    mfp4073 Long timer

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    I ended up drilling it a little and using an extractor on it. Was in JUST the same place and freaking out about having to replace a carb
    #8
  9. Wirespokes

    Wirespokes Beemerholics Anonymous

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    If you're applying enough force to bugger the threads, you're over-doing it!

    Be patient. That's the very first ingredient.

    Give the penetrating oil time to ... uh ... penetrate.

    Heating and cooling cycles make it easier for the oil to penetrate and breaks the bond between the jet and aluminum body.

    Go back and forth - tighten, loosen, but don't ever use enough force to bugger the screw head! I know, it seems weird to try to tighten it, and it seems counter intuitive, but it is one of the successful techniques.

    I wouldn't suggest tapping on the screw or the body - they're both way too soft!!!

    Another thing that's worked for me is aluminum cleaner. I always used to use a Zep product for cleaning aluminum but I can't get it any more. The next best is Eagle1 mag wheel cleaner. Don't get the one safe for clear coated wheels - it's not as strong!

    Work on it a little at a time. Say ten or fifteen minutes, and just leave it if the jet hasn't budged yet. I've been able to salvage slide carbs like the Dellortos, with stuck slides and chokes this way. So be patient, it will free up!
    #9
  10. Bill Harris

    Bill Harris Confirmed Curmudgeon

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    My experience is that the float bowl will get a dab of water-- from rain, washing or the tank-- and this can wick up into the jet threads, and if the bike is left sitting for a long time the water will corrode (oxidize) the carb pot metal (a zinc-aluminum alloy) and lock the jet in. As Wirespokes says, penetrating oil, heat cycling and when the jet starts to move, turn it back and forth as the corrosion bond breaks down.

    Tricky, but do-able if you're careful. Brute force usually results in a cha-ching sound emanating from the wallet.

    --Bill
    #10
  11. ragtoplvr

    ragtoplvr Long timer

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    learn to hollow grind a flat blade screwdriver, it makes a huge difference in holding power. Then a dab of valve grinding compound on the blade, the amount of force you can apply goes way up. Then heat the body in boiling water for about 10 minutes. They always come out for me so far.

    Rod
    #11
  12. US_Marshall

    US_Marshall Adventurer

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    My left side idle jet was stuck, half of the head was already missing when I started on it. I ended up drilling it out on a mill, even after removing all but the threads, the corrosion was so bad it still would not come out. I ended up breaking the brass threads out with a small pick. Minimal damage to the body but a new jet screwed in and tightened down.
    #12
  13. Boxer Metal

    Boxer Metal Mad Scientist

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    I agree with Cordless. I rebuild these carbs all the time and an impact used as mentioned or a 1/4 drive racket with a slotted screw driver socket works good to. There was no suggestion by Cordless to tap on the housing. Be very careful trying to fix it. You could crack the housing. If it is still useable leave it.
    #13
  14. Foot dragger

    Foot dragger singletracker

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    Sounds like new carb time,its all a learning process.
    #14
  15. disston

    disston ShadeTreeExpert

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    If you bent the housing you will probably have to post some pictures so we can see the damage. This is not good.

    Start with, just which jet was stuck? Or is it still stuck? The idle or the main jet? It sounded to me like the idle jet because you said you were using a screw driver.

    Then again the idles mix screw is made of steel and this may be more prone to being stuck. But all of the jets can be stuck at different times.

    Going slow, not hurrying. Using Heat and a good corrosion attacker, Kroil is the best in my book but there are others.
    #15
  16. LanceR75

    LanceR75 Adventurer

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    It was/is the idle jet. I took it in to a local "carb guy". I asked him to dunk the carb body as it is pretty grimey. He said he can get it out but it will most likely need to be drilled out. He was actually worried that I couldn't find another jet. I'll post pics of the bottom of it when I get it back.

    Thanks for all of the input/info, y'all.
    #16
  17. JonnyCash

    JonnyCash turd polisher

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    getting a new jet won't be any trouble. Any BMW parts supplier can get it to you.
    #17