Had the exact same problem here, with the same engine!
Replaced the coil assembly. It is a 1 piece unit that incorporates both spark plug wires.
While you have things apart, take the opportunity to clean out the cooling fins on the engine. This engine is bad for getting build-up in the fins. I could not believe the build up in mine (on a 10-12 year old Bobcat T3100). Take off as many heat covers as you can to do this.
It'll run like a new one when you are done!