CDI repair?

Does anyone know of a website that shows how to repair CDI's? I have one thats giving me fits on my NX250 and would like to give it a shot before I shell out $170 for a new one. I already have it opened up but I'm not sure what to look for.

Unfortunately, it is basically impossible to remove the plastic potting material so you can get at the components.

What kind of CDI does the NX250 use? If it is the same as the 80's and 90's XR/XL CDI it should be possible to use one of the aftermarket units that sell on ebay for $50 to $70. If the NX uses a 12 volt CDI like the XR650L you might be stuck with getting a new one. Electrex makes an aftermarket one and the part number is CD1250.

Before replacing the CDI, try and eliminate all other sources of problems, such as the stator, pickup, coil, plug ans plug wire.

Actually the back side is already removed exposing the solder joints.

I'm pretty sure its a 12 volt CDI because its e-start. Its almost twice the size as my XR600 CDI.

I've already elimated all the other possabilities, the CDI's on late 80's and early 90's are know to be a weak link.

You might try going over the solder joints with a soldering iron. A common failure is vibration induced cracking in the solder joints. It's worth a try since its easy and quick. That is one of the big reasons everything is potted in plastic.

thats a 12 volt if its that big.

+1 on resoldering. i fixed the engine ECU in one of my toyota pu's by doing this.

I'm going to give it a shot, I just hope I don't solder something thats not supposed to be. :banghead:

If its not a solder joint, it may be a failed electrolytic capacitor in the +12V to 300VAC (or 150 or 200 or whatever) stage.

If you can see the caps, look for one with a bulged case or a 'blown' lid, or with discoloration around the legs.

I think this is what kills XR650L CDIs as well.

Dave

I have been having some very annoying issues with my 650L and I think its my CDI. Your NX just dying for no reason? Is there no consistant time of death? Mine just dies at random intervals. Sometimes it will run for a couple hours and sometimes it wont start at all. When mine acts up, I just pull it out and whack it againt the frame a few times. That usually works for a while. Try it.:banghead:

When mine acts up, I just pull it out and whack it againt the frame a few times.

Hehe, that sounds kinda funny.:busted:

Hehe, that sounds kinda funny.:banghead:

LMAO!

Well, it I tap the CDI against the frame it will run for a little while then die untill I tap on it again.

Looks like I'll have to order a new one.

Looks like I'll have to order a new one.

Yup, I just ordered a new one for my 650L today.

just curious, what are the model years of your bikes that are needing a new CDI?

Mines a '93 XR650L with only 7500 miles.

funny, i see most guys that have cdi problems on L's that are pre-'95.

coincidence?:banghead:

A friend is going to let me try his spare XR650L CDI to see if they are the same. Physically they are identical, I bet if it does work the rev limiter setpoint will be lower than the NX250 one.

I've had what I thought were CDI problems on my '93 XR650L and since the CDI itself is embedded in epoxy, it's more likely that there's a problem with the wiring harness near the CDI connectors. My most successful fix is to work the connectors on and off to wear off any corrosion that might have increased impedance and then I took the CDI with the wiring harness attached and put a few twists in it by spinning the CDI a few times to put a mechanical strain on the wires going into the connector parts and then reinstalling the CDI with the strain still on the wires. Now my bike runs fine!:banghead:

Obviously you don't want to twist the wires so much that you break any of the wires...:D If this works for you then you know it's not the CDI!:busted:

funny, i see most guys that have cdi problems on L's that are pre-'95.

coincidence?:banghead:

Maybe they have a 13 year life span?

A friend is going to let me try his spare XR650L CDI to see if they are the same. Physically they are identical, I bet if it does work the rev limiter setpoint will be lower than the NX250 one.

If the cdi for the 650 will work on the 250, then it would work the other way. If what you say about the rev limiter is true, then you could swap the 250cdi to the 650 and increase the rev setpoint

Maybe they have a 13 year life span?

If the cdi for the 650 will work on the 250, then it would work the other way. If what you say about the rev limiter is true, then you could swap the 250cdi to the 650 and increase the rev setpoint

Ya but if thats the case you don't want a 650L reving that high! These NX250's are dual overhead cam screamers.

When I get my new CDI, I'll chime in on how it works and whether or not it solves my problem. But heck, you really can't blame a 15 year old electronic component for finally crapping out. My '93 has a little cam chain noise, but other than that, it runs perfectly when the CDI is working.

Ya but if thats the case you don't want a 650L reving that high! These NX250's are dual overhead cam screamers.

The rev limiter might not help, but if it has a better advance curve...

Dave

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