Pilot screw removal-replacement

Discussion in 'Carb/Tuning' started by Fire-medic, Oct 9, 2018.

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  1. Oct 9, 2018 #1

    Fire-medic

    Fire-medic

    Fire-medic

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    I got a set of carbs someone had buggered a pilot screw in, and I used a Harbor Freight left-handed drill bit set to remove the pilot screw.

    When the drill bit caught the brass screw, it unscrewed itself, and saved the carb body. Since partzilla shows this carb body for $649, I was happy to make the 'save.'

    #1: carb body needing a fix
    #2: the brass debris
    #3: at 12 o'clock, the white 'dot' is the cleared passageway illuminated by an LED flashlight from the carb throat
     

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  2. Oct 9, 2018 #2

    mabdcmb@yahoo.com

    mabdcmb@yahoo.com

    mabdcmb@yahoo.com

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    Nice work.

    Did you do anything to try and protect the the carb body threads and center the bit? Or did you just go after it with a steady hand?

    Sent from my SM-G930V using Tapatalk
     
  3. Oct 9, 2018 #3

    Redbone

    Redbone

    Redbone

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    Holy Crap, $650?!!? Wait, I have a spare rack of carbs!:punk:
     
  4. Oct 9, 2018 #4

    Fire-medic

    Fire-medic

    Fire-medic

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    I used a brand new bit. I was going to use my drill press at first, but decided to use a hand drill and the left hand bit instead. Dannymax and Sean earn their $$. I paid a machinist friend to do the last one I had, but decided to give it a go. My friend the owner of where I hang out suggested the left hand but. It worked well but thank God the pilot screw was not cross-threaded.

    I did consider sleeving the bit, or a pilot hole, but in the end, just tried a gentle approach rather than brute force. If there is a 'next time,' I may not be so-lucky. I believe the steel spring also centered the bit as it chewed into the brass and the left hand bit backed-out the remainder.
     
  5. Oct 10, 2018 #5

    sdt354

    sdt354

    sdt354

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    A 1/4" bit will follow the tunell and mark a nice center. After that it's not to difficult to drill the head and use an easy out. I usually tap a tapered easy out into the drilled head, then put the easy-out in the vice and twist the carb body.
     

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