symptoms:
no spark or weak spark
engine dies upon warming up
cause:
7 wires from main harness rubbing on driveshaft rubbed through causing total electrical failure.
solution:
removed airbox hard to access even with it out but removed all bad wires and rewired...made wires longer so to reroute to avoid same problem..works awsome now.
P.S. bristles in carb were mine as well but it was from previous owner as for carbs were redone right after i bought sled.