New Spark plug wire or how to ruin a CDI

I'm still looking for copper cored plug wire. Called all over the Phoenix area and nobody has any. Talked to a couple of small engine mechanics and they both agreed that a magneto engine should use copper cored wire and not carbon resistor wire.
 
Update. Finally found copper core wire locally! Kart & Cycle place sells by the foot.
He also confirmed that copper core is the only wire that should be used on magneto engines. Just passing this along.
 
I got my plug wire from autozone. Got the cheapest single plug wire they had, and cut off the side that went to the distributer cap. Screwed her in and no problems even with a .028 gap. If I remember correctly it is a resistive type.
 
Do bear in mind that while the primary voltage used in these ignition systems is generated by use of a magneto style induction system, the timing and triggering is accomplished by a CDI unit.
True Magnetos use a points and condenser arrangement to trigger the precise time at which the spark occurs.
A CDI unit is purely electronic in design and execution.
Quite a few CDI units will not tolerate the use of a solid copper spark plug wire for a prolonged period of time as the copper core will allow transient voltages to backfeed the CDI unit and eventually cause insulation breakdown of the components that make up the CDI's electronics.
The skinny: Copper core wire = higher performance at the cost of a reduced lifespan of CDI unit..
Resistor core wire = very acceptable performance at the cost of longer lifespan of CDI unit.

Hypothetically speaking, if I were in the business of manufacturing and/ or retailing CDI units, which kind of wire would I recommend to use?
(Hint: I wanna make lots of money.)
 
Hammond Egger said:
I have three motors. I decided to upgrade the spark plug wires because of the cheap, poorly engineered bakelite boot on the ones that come with the kit. One of the plug wires easily unscrewed from the CDI and the new one screwed in. End of problem. The second one was a different story. I tried to unscrew the wire and it would not come loose. I tried pliers and ended up twisting off the wire. Then I tried to dig what was left of the old wire out of the connection to no avail. Apparently they have started gluing the wire in with some kind of glue or something. I guess Mr. Grubee wants to make sure that his low quality parts stay on his low quality motors.
Click to expand...

What about replacing the cdi unit all together with a coil from a 50cc 2-stroke dirt bike coil, like Honda,Yamaha,Kawasaki suzuki no white wire doe any one have any knowledge of the idea?
 
An ignition coil alone does not have a triggering device to operate the ignition system.
The CDI units used on these engines have both the CDI triggering device and the ignition coil all in one neat, easy to mount black box.
Modern motorcycles have a magneto induction unit, a CDI unit, and a coil all seperate and wired together to make up an ignition system.
 
i broke off the part around the wire holding it in place.. then i picked all the crap off the screw the wire fits on. after that i set it on there, and sealed it with a wonderful glue called E-6000.. it is clear drying, waterproof and its not so strong i can never get the wire off..

i mean it will keep air, water and dirt out. but not me! and for the tiny lil plastic boot i ripped of. you cant even tell. it wont be missed.:) even if i dident have to break it off. i still would seal it just to be safe.
 
Plus there are now several replacement CDI boxes out there that use a motorcycle coil or even a 6 volt car coil if you want. A car coil is made to saturate like 8 times every other crank revolution. I think these Chinese motors fire twice every revolution. The spark is triggered by the gaps in the magnet and there are two gaps...

Upshot is a car coil, except for being large, makes a big, fat spark on a cycle. One of the earliest mods for a Yamaha RD350 was the addition of two car coils. Boosted the power quite a bit.
 
My wire was glued also it broke off inside the cdi box when I went to unscrew it. I just used a pick and scraped it out and screwed in my new wire 500 miles later still works good .
 
resistive carbon core wires DO WORK

ive been running an 8.5mm msd supercore (carbon) wire for a long time. better than the copper core it came with in terms of throttle response. looks better too, and i had it laying around the garage.
being 8.5mm, its huge and i had to trim it. no big deal

do not run a resistive wire with a resistor plug, so ive heard. i never use resistor plugs though, so i cant confirm this.

DSCF0381-1.jpg
 
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I had leftover wire from my race car. I use Mallory Sprint copper core wire. it's 8mm so I had to shave it a bit, too. I have a Honda replacement coil and it came with a Vinyl boot that stretched over the wire. I also squirted a little silicone into the hole to waterproof.
 
adb140275 said:
resistive carbon core wires DO WORK

ive been running an 8.5mm msd supercore (carbon) wire for a long time. better than the copper core it came with in terms of throttle response. looks better too, and i had it laying around the garage.
being 8.5mm, its huge and i had to trim it. no big deal

do not run a resistive wire with a resistor plug, so ive heard. i never use resistor plugs though, so i cant confirm this.

DSCF0381-1.jpg
Click to expand...

I see you have a Puch cylinder head. Which one do you have on what motor? I have the Hi-Compression head ment for a 50cc mounted on a 66cc. The compression is supposed to be astronomical, 13:1. They have a head made for 70cc and I'm thinking (although not very hard) about getting the 70cc one for less compression.

So I'm curious about what you have going :)
 
Bought the plug wire from sbp, and what do u know the stock plug wire is glued in. Going to have to use pliers to get it out. I can see some glue on the side. I hate when manufacturers skimp on quality.
 
That is not a complete CDI ignition system. It is only a CDI compatible ignition coil.
Motorcycles typically have at minimum a 3 part ignition system.
1. Alternator with ignition trigger assembly.
2. CDI unit.
3. Ignition coil.

These little engines have a much simpler version.
1. Alternator (more commonly referred to on these chat sites as a magneto, even though it really isn't one).
2. CDI unit with a built in ignition coil.

If you want to upgrade your engine with a high performance ignition try a dragonfly75
ignition. It will need that coil that you have found.
Top link, right below the picture.
GRUBEE 48cc MOTORIZED BICYCLE INFO
 
So which one should I buy... I dont want one off the bike kit vendors that have the same chinnese one that breaks down i want a high performance ignition coil.
 
WattupBaii said:
So which one should I buy... I dont want one off the bike kit vendors that have the same chinnese one that breaks down i want a high performance ignition coil.
Click to expand...

Then get one from dragonfly75.
Judging from the reviews I have read on it, you won't be disappointed.
 
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