I recently bought an '01 ls650 that had been sitting for a couple years in some guy's garage. I just got a new battery, figuring this was the main problem for the bike not starting, but now it's apparent that there's no spark getting to the engine. I know for a fact that the spark plug is good, because we took it off a working bike. The previous owner had just bought (2 years ago) a CDI box for it as well but it still wouldn't spark, and this is right around the time he stopped trying to get it working. Just wondering if anyone out there could offer up some advice on what I should check next? I'll likely have to take it to a mechanic but if it's something I could manage on my own I'd like to give it a shot.
Thanks

Incompatible CDI's have incompatible connectors.

How did you check for spark?

Check for power at the coil & check the ground of the coil.

If I remember correctly, it's a hot coil.
meaning there's power to it all the time.
until the CDI tells it to spark, then one side goes to ground.

what can happen when the key is accidentally left on for a long time, the coil will overheat and sometimes short out.  there's also a component in the CDI that will burn out.