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Resistor spark plugs

Discussion in 'XJ Technical Chat' started by biggs500, Aug 3, 2011.

  1. biggs500

    biggs500 Active Member

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    This may be a stupid question but if I am using BPR7ES (resistor) spark plugs in my 650 Seca along with the resistor plug caps is this too much resistance? The reason I have the resistor plugs is because the local shop was out of the non resistor type (BP7ES).

    The reason I ask it because I have not run this bike for the last couple of years and only intermittently before then. I am working on getting it back to how it should be but it just doesn't seem to have the power I remember. Maybe it's only my imagination as my other bike is a ZX 1400.

    I have done all the necessary maintenance (valves are all in spec, carbs are clean and bench synced with a vacuum sync planned). The bike is stock.

    Thanks.
     
  2. SQLGuy

    SQLGuy Well-Known Member

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    Adding resistors in the plugs in conjunction with the ones in the caps will alter your spark burn time and current. Although this may change power, emissions, and fuel efficiency a bit, I'm not sure it would result in enough of a change to be seat-of-the-pants noticable. Still, I'd shop around for the correct plugs.
     
  3. RudieDelRude

    RudieDelRude Member

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    I'm kind of curious about this myself. All oreilys had were resistor plugs, that's what's in the bike now
     
  4. SQLGuy

    SQLGuy Well-Known Member

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    I had no trouble getting the correct plugs from Advance Auto Parts.

    I think I had to order them (next day) to get them at Checker... which is now O'reilly.
     
  5. Ground-Hugger

    Ground-Hugger Member

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    Do not use resistor plugs with the resistor plug caps. The increase in resistance will reduce the current to the plugs and cause a weaker spark from the plugs. Result is miss fires and fouling. If you have to use resistor plugs remove the resistor caps and use the same type of plug cap that are used on cars. Non resistive plugs are used for a reason.
     
  6. biggs500

    biggs500 Active Member

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    Ground-Hugger speaks the truth. I picked up four new plus (BP7ES) and now after a ride they are all burning the same. I did have fouling issues with the resistor plugs which was causing me fits.

    Thanks everyone!
     
  7. Mr.Etobicoke

    Mr.Etobicoke Member

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    I was also having trouble getting the NGK BP7ES plugs.....so I called the NGK tech line, and they told me to run the BPR7ES plug and close the plug gap by 5 thousands. NGK clames that the non resistor plug is not available in Canada any longer.
     
  8. biggs500

    biggs500 Active Member

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    I got mine at the local Autozone. I realize that won't help if they're not available in Canada.
     
  9. SQLGuy

    SQLGuy Well-Known Member

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    Despite what NGK says, you might want to try a motorcycle shop. There are a variety of NGK parts that are only available to motorcycle parts sellers and not to NGK auto parts dealers. The NGK resistor caps are an example of this.
     
  10. mwhite74

    mwhite74 Member

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    I call shenanigans. I have a set for my Maxim, Canadian Mo-Fo sells them but they're not the base base base model NGK. Not the crazy v-groove or iridium either though... Perhaps NGK Copper core?
     
  11. KrS14

    KrS14 Active Member

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    You can get non resistor at Crappy Tire, they've always had em evertime i've been looking for them.

    Also, Using both resistive caps and plugs will NOT make the bike NOT fire. It will give you a LONGER spark, but it won't inhibit the spark completely.

    The resistance is a current limiting effect only. Instead of a quick "snap" spark, you'll get a longer, smoother spark.
     
  12. workingonit

    workingonit Member

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    I have added a radio to my bike. I was hoping to use the resistor spark plugs to help remove some of the engine noise but I dodn't want to weaken a already poor ighnition on the 550. has anyone had sucess doing this with a xj?550
     

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