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Tap & Die question

Squire ยท 2024-09-02 20:22

I'm questioning myself on the proper size tap to re-thread a sparkplug access hole. Seems like the last service may of cross threaded cyl head somewhat. Honda head taking a NGK BPR 6 ES Plug What size Tap/die to cleanup this mess? Course, fine, metric ? MM

Replies6
  1. #1MarshallPowerGen2024-09-02 21:56

    Should be a standard 14mm thread, look into a "Spark Plug Thread Chaser". It will push the existing threads in the head back into place versus a tap that will cut past anything out of place.

  2. #2Joe H2024-09-02 22:02

    You can find it a blister pack hanging in any parts house, 14MM & 18MM double ended tap/chaser. Joe H

  3. #3Squire2024-09-02 22:31

    Many thanks to all for the tool info.

  4. #4terex herder2024-09-03 13:51

    A spark plug tap is a special tap and not a standard metric tap.

  5. #5bccat2024-09-03 23:21

    Smear a little grease on the tap, saves the crud from going into the cylinder

  6. #6sid rust2024-09-05 21:04

    telex herder is correct , if you use a standard 14mm x 1.25 pitch thread tap to clean out a spark plug thread it will cut the thread oversize.