Spark Plug Wire Questions

Discussion in '2-Stroke Engines' started by Timbone, Dec 4, 2015.

  1. Timbone

    Timbone Active Member

    My motorbike i running with a old stock generic CDI with attached plug wire. I know the CDI works, but the spark plug cap is suspect. I want and have a better wire.

    I ordered an upgraded CDI with a nice NGK plug wire but it was faulty. I think the problem was a bad connection where the plug wire left the CDI body. Since it is toast, I chopped off the wire very carefully and removed about an inch of insulation. I had no idea what spark plug wire looked like. it's a thin, braided steel looking wire that looks a bit like shifter cable. After I receive a new CDI to make sure I have coverage, I intend to cut the cord of the current CDI I am using, thread the new plug cable onto it, and then solder it together nicely. I am not sure how to insulate it. At the very least, I am thinking heat wrap covered by electrical tape.

    Does anyone see anything wrong with my idea? Never messed with a plug wire before.

    Thanks!

    =Timbone=
     

  2. crassius

    crassius Well-Known Member

    they usually unscrew from the CDI - some have some glue on them to keep from falling out - if yours has glue, carefully pick it out with tiny screw driver or dremel tool, then you can just screw in the new one
     
  3. Timbone

    Timbone Active Member

    I have already cut off the plugwire from the CDI body and I have cleared off about an inch of the rubbery insulation. My plan is to solder up this plugwire adn cap to the functioning unit.

    I have these two CDI units. I am not seeing a way on either where the plugwire can simply screw into the unit.
     
  4. crassius

    crassius Well-Known Member

    CDI body has same threaded screw that plug cap has (if you have a plastic cap)

    google a bit or search here for pics of cap & wire fittings unscrewed
     
  5. Elwoodwins77

    Elwoodwins77 New Member

    The stock plug wire unscrews right at the CDI body.Once you take the wire off it's just a screw post out of the CDI. No need for soldering. I replaced my stock plug wire with a left over coil wire from a drag racing motor project a friend was working on. Screwed right onto the post. I wound the wire around the post a few times before screwing it on just to guarantee solid connections.
     
  6. Timbone

    Timbone Active Member

    Thank you very much for educating me, guys! Yes, I removed the wire from the suspect unit and I can see the threaded screw post running out of the unit. I thought that was a solid one piece unit. That makes things very simple.
     
  7. Timbone

    Timbone Active Member

    Update: I had some time so I wrapped my NGK spark plug wire up with a new CDI unit and soldered it together nicely. The NGK plugs wires are great because they screw on tightly to the NGK plug. The covered the soldered wire piece with a thick layer of Seal All and wrapped it up tightly in electrical tape.

    The fire is much better now! So, if you are wondering, you can splice a plug wire to a CDI and get more length and better spark! NGK components are the shizz!
     
  8. Frankfort MB's

    Frankfort MB's Well-Known Member

    I use accel 7mm high temp super core wire and it added an extra 2mph to top speed and is a lot smoother getting there
     
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  9. Timbone

    Timbone Active Member

    What kind of spark plug cap are you using?
     
  10. Frankfort MB's

    Frankfort MB's Well-Known Member

    The stock rubber caps with the little coils, work fine for me
     
  11. Timbone

    Timbone Active Member

    I am finished with the stock plug caps. Wen I look back on all the problems I've had, these things have always at or near the center of it. Yes, they work. Until they don't work. Yesterday I was rocking it, bike was performing brilliantly. Then I stopped the engine to check my phone. I couldn't get the bike to start for the longest time. I fiddled and diddled with the plug cap, shocked the sh!t out of myself a few times on purpose (I even felt some spark through the rubber insulation!).

    Got home any finally attached the NGK plug cap which screws tightly onto the plug. Bike has been rocking it ever since!

    No more of those for me except as maybe emergency fixes.

    =Timbone=
     
  12. Frankfort MB's

    Frankfort MB's Well-Known Member

    They tend to shock when you don't want them too lol. Shocking isn't it? ;)
    I was checking spark plug one time that wasn't fireing and it started arcing all of a sudden and I figured it out real quick
     
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  13. 45u

    45u Active Member

    BS a plug wire is not going to make that much difference if any unless the wire you had on it before was bad and if this was so it would have given you running problems. Been running THE SAME STOCK graphite wires on my Harley for over 116,000 miles. Yes I do recommend solid core wires but they will not make any performance gains.
     
  14. Timbone

    Timbone Active Member

    The real advantage of a good wire and cap is an absolute solid connection to the plug. I think back to my first build off a kit: I'd be cruising at WOT and then -?sudden loss of power! Speak plug cap dangling!

    I my experience with a handful of different plug caps, anything that isn't tightly affixed (metal on metal) is subject to cause trouble, especially at start up.
     
  15. 45u

    45u Active Member

    As I said copper is best where you can use them like on these little motors.. My CDI that came with my bike motor did not even come with a resister cap. In my opinion resister caps are not necessary. Did a fair amount of testing plugs, wires and so on with a dyno and by the numbers these items make very little if any difference in power or performance. Yes once again I agree solid core wires are best just wish I could run them on my motorcycle but with EFI no way.
     
  16. Frankfort MB's

    Frankfort MB's Well-Known Member

    the stock wire that comes with these kits absolutely suck, they look almost like they are frayed at the ends, every kit I've ever got has been like that. A wire with less conductivity will not get as much as the spark than a more conductive wire.... That's a pic of my stock wire
     

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  17. 45u

    45u Active Member

    This happens when you install it into the CDI box or plug boot no matter what wire you run. You do not even have to skin the wire back as both have a pointed screw like thing. If you do not skin back will not untwist as bad.
     
  18. So im looking for a cooler spark plug my engine gets really hot really fast i feel as though she may be overheating so heres what i run now
    Screenshot_20160503-072023.png looking at going for a 6 or 7 anyone have any recommendations on theses specs what plug would be a good one to get thats either a 6 or 7
    20160512_151859.png any help would be greatly appreciated also looking for a good recommendation on spark plug wire good quality at a good price i dont need greatest but something better then this pos stock cable
     
  19. 45u

    45u Active Member

    I run a NGK BH7S and here in Georgia it is all ready in the 90s. If you want to go colder with a NGK go higher on the number other works a BH7S is hotter then a BH8S. I have done many a test on a dyno with the high dollar plugs on air cooled motorcycles and there is no difference between them and the standard plug. All it is more ways to get more of your money. I can get 3 standard NGK for what one of the fancy plugs cost. Do a search and see what others say! I have not here on the forums but on the net.
     
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