Attempt at disassembling CDI

[Soujyu]

DISCLAIMER: I may be a scientist and that's what I do in real life, but take everything I say here with a grain of salt.

DISCLAIMER 2: I have not been able to fully disassemble the CDI yet.

I did propose to disassemble a '08+ CDI for noble purposes. Because I've been "distracted", I had some trouble keeping focused on it, as can be seen on the timestamps on the attempts so far.

This is our sacrificial '08+ CDI. Note that it isn't a very big part.... and Kawasaki insists on charging us several hundred dollars to replace this.


Note the connector. This side is actually not rigid like the other sides; this is actually pliable.


Note the seam here. (Unfortunately, it's sealed.)


So, I got a utility knife and tried to cut into the pliable side.



Here's the problem. The "pliable side" is actually the entire filler space for the CDI. Basically, I can see the PCB, but the CDI unit is this hard plastic shell, the PCB, and this rubbery/styrofoam like substance fills all the empty space. I've already taken a Dremel to the seams you see in the previous pictures. However, it will not open, which implies the rubbery/styrofoam filler probably also serves as some form of adhesive. All my attempts at prying the case open in half have not been successful, although this probably means I probably need to go to the hardware store and get some bigger tools

So, how is this relevant to our CDIs going bonkers? I suspect that Kawasaki or Denso did not really realize that our Ninjas would be operating in conditions that exceed 100 degrees Fahrenheit. Basically, because this entire unit is sealed, the electronics are cooking in there!

Anyways, any suggestion to get the case split open in half would be much appreciated.

[ztrack157]

I used a sharp hot blade when I chopped one open a year ago just be careful.

[Soujyu]

Originally Posted by ztrack157

I used a sharp hot blade when I chopped one open a year ago just be careful.

I just got half of the top half of the case off. The whole thing is filled with this crap.

Note the shiny circle there. That appears to be an electrolytic capacitor. That is one possible why under very hot conditions, our CDIs could act really strange.

(Incidentally, I've broken off a couple of capacitors just trying to get this black goop off.)

The nature of capacitors, especially electrolytic capacitors, is that they tend to not work as well in higher temperatures.

[kkim]

the black crap is potting compound (?) used to keep the PC board components isolated from vibration.

I'm pretty sure, but not certain (I've never cut open a pregen CDI), the pregen CDIs have potting compound in them as well. So why do they not have a problem like the newgens? My guess is that it's due to a bad batch of low quality manufacturer units speced for the newgen.

[Soujyu]

Originally Posted by kkim

the black crap is potting compound (?) used to keep the PC board components isolated from vibration.

I'm pretty sure, but not certain (I've never cut open a pregen CDI), the pregen CDIs have potting compound in them as well. So why do they not have a problem like the newgens? My guess is that it's due to a bad batch of low quality manufacturer units speced for the newgen.

I think you're right on that it prevents vibration (and it makes things pretty tamperproof).

The thing is that if you wanted to skimp on parts, the capacitors tend to be a prime target. Considering how much current has to potentially go through the caps, you can skimp out by using capacitors that are rated for a lower temperature. It would pass inspection at lower temperatures, but once you get up to higher temperatures, it would fail.

[kkim]

true... but I wonder if 250Rs in hotter climates (ie. SE Asia) have more CDI problems than North American owned ones?

I live in the tropics and have not had the CDI problem, which tells me that whatever is causing the failures is not across the board, but more related to bad batches of components that went onto the PC boards.

Getting Kawi to admit that would be impossible.

[Soujyu]

Originally Posted by kkim

true... but I wonder if 250Rs in hotter climates (ie. SE Asia) have more CDI problems than North American owned ones?

I live in the tropics and have not had the CDI problem, which tells me that whatever is causing the failures is not across the board, but more related to bad batches of components that went onto the PC boards.

Getting Kawi to admit that would be impossible.

Because they would lose the potential profit in getting people to replace their CDIs out of warranty?

As far as I can tell from what I've seen so far, the sum of the parts in there is NOT worth $300. I would say all the crap in there is probably worth $30. Now, granted, things like the BRT/TIS or the pregen CDIs probably have better speced parts.

The other thing is that where you are, kkim, the temperature doesn't quite hit the mark needed to make it go crazy. I know that mine goes crazy when the ambient temperature outside is around 95 degrees.

I'll probably figure out more once I can get the other half of that cover off and get the goop off.

[Soujyu]

Oh, BTW, do take my words with a grain of salt; I'm just trying to figure out for myself how this little box can cause us this many problems.

[HKr1]

Good luck on getting that crap out of there.

Poking around found:

There is one method which has a possible chance to working, you rapidly heat and freeze the epoxy, this will have the occassional result of "popping" the epoxy off of the pcb without damaging the components underneath, but this method will most likely destroy several dozen boards before you are successful.

And this other guy did an x-ray to see what he was dealing with, then started cutting away

http://www.multigame.com/pacplus.html