Had my FIL's A cutting down some over growth in our lower field on Monday with the A and a pull behind sickle bar mower. I shut the A down to take a break and put some gas in it. When I tried to start it up it would just turn over with not a hint of firing up. After a number of attempts, I gave up and my BIL towed the A to the barn. Tuesday morning I went back to the farm and tried to start it again since it would be a cold start. Just cranked over and would not start. I pulled a spark plug wire and put a spare plug on it and grounded it to the block. No spark. I then tried an in-line spark tester just to make sure there wasn't any spark. Nothing on the tester. I know it has an IH H4 magneto on it. I've never done any work on the magneto other than putting a cap and rotor on it a few years ago. I don't know where to start or what to check out first. My FIL passed away in March of '18 and I don't know if he ever had anything done to the magneto. I'm sure nothing was done to it in the last 10 years that I know of. Any help/tips/tricks/guidance would be greatly appreciated.