New spark plug bpr6hs

Discussion in 'Electrical' started by aaronwilde, Oct 17, 2011.

  1. aaronwilde

    aaronwilde Member

    So I went to LORDCO in burnaby while I was grabbing a new magneto and expansion chamber.

    I did some research and figured I may as well get a better quality spark plug while I'm upgrading my parts and correct me if I am wrong but the NGK b6hs or bp6hs or bpr6hs would all work right? or 4/5/6/7hs etc.

    I came to the conclusion 6hs would be the best for general activity.

    So now when I compare my chinese stock plug that came with the engine and the new NGK bpr6hs they do not seem the same.

    Here is the picture comparison side by side. Is the slight difference in length okay?

    How come it is slighty different when these forums cearly say it is the best replacement plug?

    2011-10-17 13.06.04.jpg

    2011-10-17 13.08.33.jpg
     

  2. motorpsycho

    motorpsycho Active Member

    yeah you should be fine, but to be on thesafe side:
    screw the ngk in and turn the engine over by hand to make sure that the spark plug does not hit the piston. If it does, you'll know.
    The stock chinese plug is too shallow as it is, and the electrode doesn't go far enough into the combustion chamber.
    The electrode is actually shielded a little by the hole in the head (combustion chamber)
    the ngk will protrude out of that hole in the combustion chamber slightly which will burn the air-fuel much better.
     
  3. HeadSmess

    HeadSmess Well-Known Member

    arrrrgh! why this topic so much lately?

    b is thread size.

    p is a projected point

    r is a resistor

    6 is heat that could be 5 or 7 but 5 is sorta hard to find around here

    h is thread length.

    b and h is all that really matters. thread size and length. get these two right and youre laughing

    p is nice in theory but probably makes no difference. unless you hit the piston...

    r is for suppression that can be done by the ignition lead/plug boot/plug/plug. nothing wrong with suppression.
     
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