Plug wire to CDI connection.

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Geoinvt

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Apr 14, 2014
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I've read where several people have said to replace the standard plug wire with a decent one. How exactly does one do this. Isn't the plug wire attached inside the sealed CDI somehow? I'd hate to pull the wire out only to find I can't attach a new one. It can't be just stuck in there could it?
Thanks all,
Geo in vt

PS: As a new member I have to say its amazing how helpful everyone has been. I'm looking for those posts that I can maybe help return the favor with.
 

2door

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Sep 15, 2008
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If it ain't broke, don't fix it.
Unless the spark plug wire is too short for your installation there is no reason to replace the kit wire. It is at least metallic core (conductor) and is better than most auto parts store wire which will be resistance wire.

Do replace the kit supplied spark plug boot with a good automotive quality part and use a spark plug with the top cap installed. The kit boot is junk and will eventually cause you problems down the road.

Keep in mind that the newer CDIs have the wire glued in and will require some careful digging to allow you to unscrew it. There is a small threaded contact in the CDI that screws into the core of the wire. Don't break it off.

Tom
 
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dodge dude94

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Jun 8, 2012
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FWIW, I replaced my wire with an auto coil wire and it made my engine perform more reliably and smoother.


I took a pair of channel locks and wrenched the crap out of the wire. Mine did have some glue in it,but it all came out with the old wire. I then just screwed my new Bosch wire in and off I went.


Annnnd 1000th post. lol
 

Simz

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Aug 11, 2017
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Am new hear myself and just seen this post... Ive replaced mine (1 of few ideas due 2 starting difficulties) 4 simple fact that the boot fits loosely over plug & just seams 2 be dodgey and of low quality. So I ended up finding an old trail bike plug lead laying around and decided 2 swap em over. The small question/query I have is where it fits on2 the CDI (since there sealed and u cant open em) ive just soldered it on2 that little thread of screw thats sticking out top of it.. Is this fine & a good idea considering I still cant get her 2 fire up (but can b 1 of many things) ??
 

crassius

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Sep 30, 2012
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not sure what you mean - if CDI was glued, then removing old wire should let you just screw in a new one easily - soldering on a CDI might fry the delicate electronics inside
 
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2door

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I agree. I wouldn't solder the contact in the CDI. The screw threads will suffice but you must make sure the screw is threaded into the wire's conductor or core of the wire. What some people fail to realize is that most new wire you buy today, unless you specify metallic core wire, will be resistance wire that has no metallic core but instead a carbon impregnated thread. That thread is very small in diameter and unless you get it threaded into the CDI correctly you're defeating the purpose of replacing the wire.
Also 'resistance wire' has a higher resistance that one with a metallic, preferably copper, conductor. As I said above, "if it ain't broke, don't fix it". The kit supplied wire in most cases has a metallic conductor. The kit plug boot is usually the culprit when it comes to poor ignition performance. Replace it with a good automotive quality boot available at auto parts stores.

Tom
 
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allen standley

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Oct 22, 2011
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In my beginnings, I have used Auto RF resistor plug wire on my bike. Seems if memory is correct-- I went through a period of mag coil replacements (2 or 3 that single year). Could be coincidental. I did a wound copper after the last replacement and havn't had a prob since. I avoid resistor / carbon plug wire. It does what is supposed to do resist. Burns out mag while doing it.
 

Simz

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Aug 11, 2017
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Ok I am fairly new to the hobby & these little 2-stroke engines, I bought a pushy 2nd hand and already made/built, so thus basically inheriting sum1 elses problems!
Tha
 

Simz

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Ok I am fairly new to the hobby & these little 2-stroke engines, I bought a pushy 2nd hand and already made/built, so thus basically inheriting sum1 elses problems!
Thanks for the advice & insight tho, so u all reckon that my soldering a new lead onto the CDI thread was a bad idea and couldve possibly caused damage?? Guess I mite have 2 try hook up an ohm meter and see if I can get anything..?