i'll bet a 6pack that it's the coil.
When they begin to fail temerature will shit them in a hurry, not just hot but warm.
measure one, put it in the oven at 80*C and measure it again.... shot coil.
They're cheap, spring for a new one.
I won't even begin with litany of issues that went back to just a coil.
Put a plug on the coil output and ground it, away from fuel, farts and anything else that might try to ignite. Crank it a second or so and you'll get lightening, if it's just a zippo lighter then your coil is shot. If you crank for about 20 seconds and the spark fades, your coil is shot.
If you have a heart attack from the shock remember that this was only advice and I absolve myself of all responsibility and your coil is probably good.