I agree not saying it can,t be but your symptoms don,t sound like a typical CDI failure.I,d be checking the carbs imho.Make sure to give them a good soak overnight in carb cleaner if you pull them apart.
Those engines don't have thermostats and won't run right until there fully warmed up. I know out xc 700 will spit and sputter if you don't let it warm up for 10 mins. I would pull the carbs off and clean the jets. Make sure the pilot holes are completely clean. Make sure you have fresh gas also.
A forum community dedicated to snowmobile owners and enthusiasts. Come join the discussion about performance, racing, troubleshooting, trails, maintenance, riding tips, modifications, classifieds, gear, and more!