I have a cougar that had the same problem, I found it was the cdi unit, it has dry solder connections. either get a new cdi unit or (if machanicley minded) carefully cut through the 2mm rubber and expose the contacts opposite the plug itself, carefully touch as many of the connections as you can with a soldering iron, then seal back up with silicone this sorted mine out and runs fine now. hope this helps. :)
L1zzard
December 2013