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

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

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

Mezo.