No spark - Bad coil?

[WoodLoon]

My '89 Husky 50 Special has been hard to start for a while. Recently it started shutting down after 15-20 minutes. Now I can't start it. I get no spark (new plug, grounded to cylinder).

I recently replaced the jug and piston with a kit from Bailey's. The above conditions started well before that and continue now, but I don't want to neglect any info that might be useful. I do NOT have a tach or compression tester that work on the saw, but when it ran it ran great.

1. Is it logical to replace the coil?
2. If so, any practical way to avoid spending $70? Is a used coil worth considering (if guaranteed it will work initially)?

Thanks

 

[watsonr]

Pull the kill switch wire to remove any ground that may be there just to be sure. BUT, the run for 15 minutes until warm and die syndrom is a bad coil indicator. Starts after its cooled down and then dies again, no spark when warm but does restart later......Yep, new coil or a good used one is called for.