If just #1 has no spark, very carefully remove #1 wire and switch with another about the same length and see if the no fire plug moves. If it does its the wire. If not, switch the plugs and see if it moves, if it does change the plugs (don't use Champion, they are now making junk. AC work well for me). If the wire and plug trick doesn't resolve the problem then dig deeper. Plugs and wires are usually the culprit before a mag on a tractor that has set a good while.