You often can't see spark in the daylight. You need a dark room to check. You can spin it over with a drill if you don't have a starter. A magneto needs to turn pretty fast/hard to make spark and it is difficult to see the spark while you are trying to flip the engine over sometimes. The only wire that should be connected is the spark plug wire. Any other wire(s) coming from the coil or mag should not be hooked to anything. The regular size wire coming off the magneto is grounded to stop the spark and therefore the engine.

Do you know that it had spark when it was in the chainsaw? Or was the chainsaw not running and retired for that reason??

Also, I make the air gap on the mag the thickness of a regular business card. Try with a new plug gapped to .025".

AV8TOR