22 hp kolher

i got a model ch22s spec. 66545 that has no spark. it has 2 coils[mags.] and a speed advance box. can anyone tell me if this engine has a history of losing spark to both sparkplugs. seems like to me that both coils would not go bad at the same time or does the speed advance control the coils. this garden tractor ran good one day while sweeping leaves and i come to put on the snowblower and now no spark