Successful 81 exciter 250 cdi ignition box rebuild

My CDI went bad. I started getting popping and intermittent throttle on accel. So I took a deemed to the CDI plastic case and what I found was pretty cool. The mother board a couple capacitors diodes and resistors. Since Diodes and resistors usually don't go bad I went straight for the capacitors. After identifying the capacitors and went to radioshack got them and 20 minutes of soldering later I have a working CDI.screw paying Yamaha 400-600 bucks for a new one. The capacitors is pretty much the only part that needs replacing. Picture attached

Top is before bottom is after

Tips.

This solder has lead in it so do this outside or ina well ventilated area.


Yamaha covered parts of the cdi with glue so try to remove it off the caps first


When trying to get the old caps out melt one side then push the cap to one side, let the solder cure then melt the other contact push it to the other side etc till it walks out of both holes.

Also the polarity is marked on the chip BUT one is marked incorrectly so use the capacitors orientation as your orientation key.

Good luck!

Awesome fix man......many arent open to doing this kind of repair and people like yourself open the door for others to do it as well

Nicely done!


Some of them are completely filled with resin and are effectively impossible to repair, but for those that aren't you have shown a light into a dark tunnel.


In the immortal words of the farmer from "babe": "at'll do. yes, at'll do"

I figured out it was my ignition box based off another thread where the guy (and me) had problems with his bike cutting in and out from idle to mid range. It usually got better when fully warm but it was still a problem. Capacitors usually do this when they absorb moisture, they are as good as dead by this point.

People are usually pretty intimidated by this stuff but the way I see it is like this

There are two parts to a ignition box, the microchip( pictured on the right) and the electrical management area i.e. The capacitors, diodes, and resistors. These are all easy to replace. If you think about it your just messing with a metal glue gun.

Just get the parts and swap em out.

Nice troubleshooting,nice cost effective fix!!!