If tors has failed it won't start at all , you can unplug the tors and if it then starts then its the tors , if the carb is dirty ( probably is unless the owner was a neat freak ) it will idle rough and hesitate , but a filthy air filter will cause those issues too.
Heres the Ugly Truth . If you like the Blaster , and Really want one you are in for a love hate relationship , BUT once you fix all the little stuff , then modify the big stuff and finally learn how to ride that pony you are gonna have a sick quad that can hang with a lot of bigger bikes , and we all know how much fun it is to make a guy on a 10k machine feel about 2 inches tall when he gets roosted by a blaster . Fun Stuff ......