I have a no spark issue and have some questions for experienced minds. Part for the 85 125 ALT are becoming scarce to find. They no longer make the cdi boxes for this year make and model. For those who do not realize it the cdi boxes from 83-86 for the 125 ALT, 185 ALT, 125 LT and 185 LT all have the same part number. I checked on partszilla and compared all 4. Even with that being said i'm still not sure if the timing curve is the same for all 4 cdi boxes? or if the timing curve is determined by the engine? I was wondering if you can use either cdi box for any size motor mentioned?

 

If they have the same part number, they will be identical, as the part number is how the stores identify which part to sell. Timing curves on nearly all bikes are set by the CDI or ECU but, back in the 80s, a few still had the mechanical bobweight system (Honda 200 range for example). Faulty stators can cause a lack of sparks, as can a faulty ignition coil, so do the tests before assuming it is the CDI at fault. A bad earth to CDI will blow it, so you need to know the wires to the CDI are right, before fitting a new one.