spark plug gap

Discussion in 'Motorized Bicycle General Discussion' started by nmason, Jul 22, 2008.

  1. Finfan

    Finfan New Member

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    The recommended gap for the stock plug is .038 which is pretty large, but it works so I'm not messing with it!
     
  2. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    Anywhere from .020 to .035 is sufficient. Most run them @ .020-.024. I guess it depends on the derections as to what the suggested gap can be.

    I have a Livefast economotor I just set up, and it is the first of many to have a bright blue spark with all stock components. I gapped the plug @ .035.
     
  3. donuts31

    donuts31 New Member

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    The gap isn't critical on the HT engines unless you are pulling juice from the white wire then the gap needs to be on the smaller end.
     
  4. Dave31

    Dave31 Moderator
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    Welcome to the forum :)

    I run mine at .023, but like BikeguyJoe says - .020-.035 should be fine.
     
  5. Down_South

    Down_South New Member

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    Hey ya'll,

    I just wanted to share a neat (stupid) trick I learned while fooling around with NGK spark plugs. I've been using BPR6HS and BPR7HS plugs with my bike. I've noticed that the 7 plug runs a little too cold and the 6 plug runs a little too warm (each plug's gap is .025"). Well I took my 6 plug and adjusted the gap to .030" to cool the spark down a little. The bike runs just fine now .boogy1a

    I've also fooled around with the carb settings to see if that would help, but I end up having to set it a little rich to get a decent idle.

    Thanks,
    Down South
     
    #25 Down_South, Dec 21, 2008
    Last edited by a moderator: Apr 26, 2009
  6. thatsdax

    thatsdax Member

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    Yes.. A wider gap delays spark, smaller gap advances . That is about the only way to change spark timing on these little 2 stroke motors. Enjoy the ride..
     
    #26 thatsdax, Dec 21, 2008
    Last edited by a moderator: Apr 26, 2009
  7. Rnroutlaw

    Rnroutlaw New Member

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    Hey all how ya been? I was just wondering what gap to set my plug at for my 80cc engine kit. I am trying to see if I can get a better start out of my engine.
     
    #27 Rnroutlaw, Feb 10, 2009
    Last edited by a moderator: Apr 26, 2009
  8. Norman

    Norman LORD VADER Moderator
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    I run mine at anywhere from 0.017 to 0.020 thousands. I run my bikes with lights so if you don't use lights off the white wire you can gap it more. Play with the gap and find what works best for you.
    I do use the stock spark plugs and I have 1 champion plug.
    I modify the ground electrode on the china plugs and somewhere in the classic posts there is a picture of the plug and how I modify it.
    being its a 2-stroke I try to run the cheapest plug I can find. So far I've had 1 china plug fowl out and could not keep it from fowling out so its in spark plug heaven.
    I use a tiny dab of neverseize on the threads to, help prevent the plug form galling the threads.
    Norman
     
    #28 Norman, Feb 10, 2009
    Last edited by a moderator: Apr 26, 2009
  9. ibcnya

    ibcnya New Member

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    (.022) I googled and came up with .019-.022 for top end speed and a little bigger for more low end.
     
    #29 ibcnya, Feb 11, 2009
    Last edited by a moderator: Apr 26, 2009
  10. philymitch

    philymitch New Member

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    How does the gap for the spark plug affect the way the motor runs? My spark plug is gaped at .025 and my motor will spit and sputter a little. My motor ran fine with the old plug that I had in it so I don't think it is rich or lean. When you change the plug style do you have to play with the gap to see where the motor runs best at? Should I increase the gap by .005 each time or what is a good number to use in this case.
     
  11. Outrunner

    Outrunner New Member

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    Make sure you're using a good quality spark plug, like NGK.
    I think they're the best. They resist fowling and last a long
    long time. Your spark gap should be about .020 - .022", if
    the gap is too wide it will require more current from your
    CDI unit to make a hotter spark, and you may be a little too
    rich on your carb needle setting if the plug looks black and sooty.
    I suggest getting a new NGK plug, you can always use a spare.
     
  12. PikeHook

    PikeHook New Member

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    What are they suppose to be at..I'm running a NGK B5HS..I know I read it somewhere but for the life of me I can't find it...
     
  13. NunyaBidness

    NunyaBidness Active Member

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    may need to read a few to find exactly what you want but it's there somewhere.
     
  14. PikeHook

    PikeHook New Member

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    Got it..Thanks for the quick reply..
     
  15. NunyaBidness

    NunyaBidness Active Member

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    glad I could help
     
  16. NEAT TIMES

    NEAT TIMES New Member

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    Pikehook, Welcome. There Are Some Members Close To You. I Am From Wi. About 80 Mi E Of Twin Cities. The Ice Must Be Off Of Mil Lacs Now. Ron
     
  17. Alson

    Alson New Member

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    my friend has a 66cc SkyHawk, anyway he had a hard time starting his and our instructions said to gap it at .036, so I told him to go to .028 so he did and lost top end, so now he runs it at .034, !now has his top end back, we run our oil mix at 25/1
     
  18. bairdco

    bairdco a guy who makes cool bikes

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    i've been running all mine at .030 lately. no problems at all.
     
  19. StealthJPL

    StealthJPL New Member

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    Hey guys, I am going to google this but I was wondering if you know who makes the 80 cc engine. I know it is chinese, but does anyone know the name of the company. I am going to replace the cheap ass chinese gaskets that are made out of a crude paper with high quality american gaskets. Any pointers would help. Thanks.
     
  20. NunyaBidness

    NunyaBidness Active Member

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    I think the only way you're going to do that is to get some good gasket material and cut your own gaskets, using the stock gaskets as templates.
     

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