I believe your all right he's milk in me. The gas is only 2 weeks old. The cylinder is perfect, just put a new spark plug in it. When I get the carb I'll post a pic.
Something else you should consider looking at, is possibility, of the spark plug, or other wires grounding out at a bar spot in the wires.
While your cutting, it get grounded, by a bad wire, and when you go start it, the wire gets jiggled away from being grounded, and when your cutting, gets jiggled back to being grounded.
How is the points, and condenser, or the ignition coil?
Could have a weak spot in it.Is the spark strong or weak? I don't think your problem is fuel related, but something else, electrical. If it was fuel related, it would try and still run. Bruce.