How to test a CDI box

[scottieh]

Hey all, I'm beginning to rebuild a 1981 XT500 and I have a no spark scenario. I have done a lot of testing to isolate the issues and I think the CDI is fried. My two pickup coil wires test within spec from the stator, and my ignition coil tests within spec for the primary and secondary wires. I jumped the wiring harness from the CDI to the ignition coil and still no spark. I have continuity between the CDI and ignition coil wires within the harness.

Does anyone have a method for testing the CDI? I've read you can use a DVA adapter (https://www.amazon.com/Electronic-Speci ... B0093U3TFG) to test the peak output voltage of the CDI but I've never done this before. These early model CDI bikes apparently had a bad reputation for CDI's going bad. Am looking to do a full check of all systems before throwing money at a problem

[motorang]

The best way would be to lay hands on a borrowed CDI which is known to be OK, and test it on your bike to see if the rest is OK.
Or send your CDI to a fellow rider who could test it on his XT500 with the rest of his bike in working order.

As I stated in you other thread - you can spot a broken coil or pickup by static DIY measurement, but you hardly can spot if one is good (AKA working under real life conditions).

Andy

[Mezo]

We have had this discussion before, most of the time its dry joints.

Mezo.