[Nrb412]

My bike was sitting on a stand in my garage at an idle and shut off. From that point on, I can?t seem to get it to start and run. If cold, it will start for a few seconds then shut off. It won?t fire again for a day. It then does the same thing again. I took the cdi from my sons xc 300 and installed it and it runs. In fact starts on first kick. The gp cdi won?t start the xc either. The cdi was sent to get reprogrammed and I got it back today and it is still doing the same thing. I guess I?m looking for an idea what direction to go from here. Any ideas would be appreciated since I?m stumped.
Btw, I bought this bike new and I?ve never had issues before this.