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Lighting and Electrical Things that go ZOT! Ignition components, batteries, lighting and accessories

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  #1  
Old 06-28-2013, 10:19 PM
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Scott.D.Lang Scott.D.Lang is offline
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Question CDI question

our kit cdi's are junk so what is to stop us from useing a 6v coil from something else a MC or even a car? it may be a stupid question but if other cdi's are better why not use them?
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Old 06-28-2013, 10:37 PM
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Default Re: CDI question

Quote:
Originally Posted by Scott.D.Lang View Post
our kit cdi's are junk so what is to stop us from useing a 6v coil from something else a MC or even a car? it may be a stupid question but if other cdi's are better why not use them?
...i'm still a noob myself bro but the way i understand it is that the stock CDI's are fine so long as you replace the plug wire and boot which is crap and should be replaced with an auto grade plug wire, ...and not a 'resistance' core plug wire, a 'wire' core plug wire is what you want.

...but like i said, i'm still a noob myself and my stock CDI is working just fine with the new wire and plug.

peace, bozo
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Old 06-28-2013, 10:51 PM
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Default Re: CDI question

The CDI is more than just a coil. It determines when the plug fires. Simply replacing the CDI with a standard ignition coil just won't work.

It is also a myth that the kit CDI is unreliable and trouble prone. They perform well and will produce sufficient current to fire the plug for thousands of miles. If they were as bad as some people try to make them sound you'll have to ask yourself why most race bike builders rely on them instead of some of the overpriced placebos available.

I also concur that you need to replace the kit spark plug and boot, especially the boot, to assure good performance from your ignition system. The kit plug wire is in fact superior to some of the resistance wire you'll get from auto parts stores. At least it is a metallic core wire which is lower in resistance than the parts store version. The biggest problem with the kit wire is that it is usually too short to allow mounting the CDI anywhere but close to the plug, usually on the bike's downtube. The insulation isn't the best quality either and is prone to cracking prematurely.

Tom
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Old 06-28-2013, 10:54 PM
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Default Re: CDI question

I also use the stock CDI with an upgraded plug wire.....works great!!

The difference between a Rolex and Timex is $$$, but they both give the very same info.
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Old 06-28-2013, 10:56 PM
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Default Re: CDI question

A CDI from a scooter with a coil as well . RCMachine (Freds Head) has a head with dual spark plugs and the last time I saw one on e-bay he had suggested using one of those little orange CDI box is with two coils to power both spark plugs. It was on like the second picture . Or build modified CDI , or buy a Jaguar cdi&coil.
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Old 06-28-2013, 10:58 PM
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Default Re: CDI question

thanks both of you. and Tom I was thinking that the cdi was much more then just a coil just was not sure. the reason I asked this question is either my stader in my new engine is bad or for some reason my cdi went out. tomorrow Im going to take the cdi off my sons bike and see if it will run then if not Im going to take the stader out of my old f50 and put in the f80 Im hopeing that I just had a weak stador and it went bad since I have one to replace it lol.
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Old 06-28-2013, 11:03 PM
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Default Re: CDI question

Scott, I hope you know there's a way to meter that out and check it and see what's wrong .
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Old 06-28-2013, 11:09 PM
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Default Re: CDI question

Scott,
There has been a lot of discussion about the potential for damaging the CDI by spinning the engine without a spark plug attached and grounded. The general consensus is that it is very possible. This is probably why so many CDI failures are reported and my belief is that the kit spark plug boot is the culprit. They are notorious for falling off, breaking or not making a good electrical contact at the plug. If the boot is failing to provide that connection then it is very possible for the CDI to be damaged by the induced current that will take the path of least resistance and potentially ground to a component inside the CDI and therefore causing it to fail.

The kit spark plug boot should never be installed and should go in the trash along with the kit instructions when the buyer first opens the kit box.

Tom
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Old 06-28-2013, 11:17 PM
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Default Re: CDI question

So, true Tom.
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Old 06-28-2013, 11:19 PM
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Default Re: CDI question

oh and tom I do belive that the stock wires are junk as everyone sez not doughting that at all just to cheap to replace things if it will work for a time
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