You haven't proved it's the spark yet. Take the plug out, plug it in the coil, ground it to the motor, and pull it over (best in poorly lit area).
1996 Arctic cat ZR 580- 6 inch risers, C+A powder skis, 99 ZR's front suspension, freshly rebuilt engine
1992 Ski doo mach 1 617cc (the beast)
Die hard polaris anti-fanatic!
Do the snow dance with me!!! We don't get enough in Vermont!
And God said: "Let there be snow."