I Have a bme 50 with ch ignition. I am new to gas, a few guys at the feild noticed my engine seemed to hicup or skip every once in awhile they thought it was needles setting then after I landed on my third flight the engine just shut off I then started it and it ran for about 15 seconds then shut down again, I was then not able to start the engine again. We pulled the plug no spark. When I got home I pulled the cowel off to investigate and found when I pulled the plug I now had spark I tinkered with it looking for a loose wire and then the spark stoped but did not seem to be related to and wires. when I turn the ignition on I get a spark and thats it if i turn the engine over some times I will get a spark for 2 or 3 turns but then it just stops and sometimes I can't get a spark at all. I removed the sensor and tried rubbing a magnet over it and was able to get it to fire once or twice but then that was it. I am new to gas and could use any help you can offer. What would be the fastest way to solve this problem so I can get back in the air.

Thanks,
Rob