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Message: [QUOTE="jaguar, post: 784663, member: 19340"] My CDI, ignition coil, and stator coil all bit the dust after I failed to tighten up the screws sufficiently on the stator plate upon reassembly. A local technician replaced the SCR and rewound the stator coil, and I bought a generic ignition coil that has 1.5 ohms on the primary. It works but the spark is weaker. Hopefully soon I’ll have an original KDX ignition coil put in. I’ve heard that due to moisture condensation it is common for the stator coil to lose good contact with ground (chassis common), so it is important to keep those contact places clean. I also imported a used CDI and ignition coil (both not working. The coil primary only had .2 ohms whereas it should have 1ohm) from a normal KDX and I took the CDI apart and replaced its SCR and it works now. I will also replace the capacitor once I receive it in the mail. I suspect that the capacitor starts to leak after it gets hot.(They do pass spikes of considerable current to the coil). I didn’t even know that these CDI’s are repairable but now I see that they utilize common components and no type of “brain” integrated circuit.(it doesn’t have any IC’s). So from my experience I want all to know that CDI’s can be repaired. The repaired CDI from my KDX 200SR (Intl model) was repaired and then sealed with epoxy before I got to look inside. From calculating the input resistance (by applying -9 volts across wht/red and black wires and measuring the current and then calculating the resistance. 9 - .6 (voltage across diode)=8.4, 8.4/current=resistance) I found out that the SR CDI uses 27 ohms, whereas a regular KDX CDI uses 16 ohms. If you try to measure the resistance (from the wires before tearing into it) with an ohmmeter it won’t read anything if it is not applying at least .6 volt, which is needed to turn on the diode. But I really don’t recommend this method since the outcome depends on the meter used. But testing the CDI’s on my bench at 3000rpm (50hz) I saw that the spark timing is just a tad later on the non-SR CDI (look for the small voltage change after the signal goes negative), although maybe the timing curve is different at high revs. The following drawing is the CDI schematic for a normal KDX (not SR which may have other part values different other than the input resistor). At [url]http://www.geocities.com/a57ngel/moto/CDI.html[/url] are the schematic, parts layout on the circuit board, board layout inside the CDI box, simple testing circuit, and voltage waveforms at three places. The parts most likely to fail, in order of liklihood, are the SCR, 1.5uf capacitor, diodes, and 16 ohm resistor. I would say to always replace the SCR (Radio Shack sells a good 4A/600v SCR which I used with success), and if the ignition coil is reading less than 1 ohm on the primary side then also replace the 1.5uf capacitor (which was allowing too much current to pass to the coil). Test all the diodes and the 16 ohm resistor and replace as necessary. To get to the parts you'll need to cut the top and sides off of the plastic container. (yes, essentially butchering it. You can replpace the box with the one listed below). Be careful because the bottom of the parts board is almost butting up to the top of the container. I have read that soaking the exposed silicone (which encases all the parts and is mixed with white stones) in acetone for 3 days will dissolve it or at least loosen it up a lot. I haven’t tried that since I can’t find any acetone here. You can dig out the silicine/stones with a knife but go slowly so as not to damage components (especially the large yellow capacitor). Go to [url]http://www.geocities.com/a57ngel/moto/CDI.html[/url] for more... :ride: [/QUOTE]

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