Ok... here is my story. I have a 2006 Yamaha Bruin 250. It needed a few things and I actually found a 2005 Yamaha Bruin on Craigslist that someone was selling for parts. I took what I needed from the 2005 and was going to sell it for the remaining parts. However, it isn't that bad of a bike and if I can get it working I may sell it for more. However it has some sort of electrical issue and isn't getting spark.

For troubleshooting... I decided to swap parts from the two bikes to see if I could isolate the issue with the 2005 parts bike. The previous owner indicated that the CDI was new since that was one thing they were told could be causing the issue. Here is where things get interesting.

Remember... no spark with the 2005 parts bike. If I take the supposedly "new" CDI from the 2005 parts bike and put it in the good 2006 Bruin... the 2006 Bruin won't start. So... I thought I was on to something. Bad CDI again?? Well... not necessarily. If I take the good CDI from my 2006 Bruin and put it in the 2005... it won't crank. I put it back in the good 2006 and it fires right up.

It seems the good CDI from the 2006 bike generates a nice spark if you hold the plug against the engine block. The supposedly "new" CDI that comes from the 2005 parts bike seems to generate a small spark on the good 2006 Bruin... but not enough to turn it over.

Since neither CDI works on the bad parts bike... something else is definitely going on. Does this sound like a short somewhere?? Could a short have killed the supposedly "new" CDI?? I'm interested in what anyone may have for ideas.

Thanks!!

 

i am not sure if the two bike parts are the same BUT i think so! You could have an bad stator or voltage reg\recfi. or switch problems [etc.] has serval componants that makes fire! I guess I would get an manual to test! or you could start trading parts off the other till you find problem! Get an hot batt. on it then try the common part failure first other than the CDI would be voltage reg\recfi. But it is an guessing game without the more infromation on readings of componants!