Burnt another cdi

the stock ones are garbage, there's no way to repair them as they are solid units :(

perhaps you can ask another member who makes CDI's to make you one :)

then you are able to change out individual parts if they fail :)

the home made CDI's depending on who makes it can have retard, spark strength and other options :)
 
Donkeyboy said:
If I had a schematic of a CDI I would make one....The stock ones are good for about 250 miles...
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Huh? 250 miles? That's not even enough miles to break in the engine! I have 750 miles on my bike this summer, no cdi issues. I am wondering why you burn up so many?
 
Yes I know...If yours hasn't failed yet, you are on the lucky side...They are not very reliable. Great motors...but the electronics leave something to be desired...
 
I am sitting here at the house...and the weather is nice. If my CDI had not failed, I certainly wouldn't be here!
 
Donkeyboy said:
I am sitting here at the house...and the weather is nice. If my CDI had not failed, I certainly wouldn't be here!
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What kind of spark plug are you running? What are the symptom of the failure? Can you see/smell something burnt/melted? I know "quality" isn't a word I would use to describe the stock CDI, but I think 250 miles is more than a bit premature for a failure!
I would guess early failures would be result of solder joints breaking, how do you have your CDI mounted? Is it subjected to excessive heat or vibration? Somethings up if you killed 2 CDI's in 500 miles IMHO.....
 
I've never had a CDI fail and all of my bikes/engines have over or close to 1k miles. You're doing something wrong if you're only getting 250.
Tom
 
I know about blown CDI's. I have never blew one myself, but my friend is notorious for blowing them. He has went through about 5, and all of them blew more then 20 miles from where we live and we sat trying to figure out what could be wrong. Luckily, the last one that blew we were close to a friends house and I just bought one off him. :)
 
F_Rod81 said:
I know about blown CDI's. I have never blew one myself, but my friend is notorious for blowing them. He has went through about 5, and all of them blew more then 20 miles from where we live and we sat trying to figure out what could be wrong. Luckily, the last one that blew we were close to a friends house and I just bought one off him. :)
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Maybe the CDI is mounted to the same tube as the motor and is getting a lot of vibration transferred to it? I think it's gotta be vibration killing the CDI's on these bikes that kill them over and over again....
 
Maybe if you build your own CDI, it might work better for you.

If a homemade CDI fails, at least you can see exactly which part failed and install a heavier-duty version of that part.
 
rohmell said:
Maybe if you build your own CDI, it might work better for you.

If a homemade CDI fails, at least you can see exactly which part failed and install a heavier-duty version of that part.
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If they fail so soon, and so regularly, I gotta figure it is from connections going bad rather than components failing? I have over 800 miles on my cdi, and I know there are lots of people with thousands of miles on a CDI without a failure. Unless the system is modified some way or another that is stressing the CDI, you would think a stock motor wouldn't have CDI components fail so fast when they last well for others. Specially several CDI's in a row, I can understand one fluke bad unit, but not several unless there is a bad batch of CDI's out there?
My guess is if you build your own you will have no more failures. Probably not because the components are better, but because your soldering and connections will be better than what is inside the stock units. Also because you will probably mount the home made unit differently and a CDI mounted differently might absorb less vibration...
I would find it interesting to dissect one of these dead CDI's to try and see what is going on here, and just have a look inside the box for curiosity sake....
 
What do you gap your spark plug to? The larger the gap the harder the CDI has to work to get the spark to occur. .020" to .025" is a good range for these weak factory CDI's.
 
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