I just bough 3 more Gravely's and now have 4 L's. They all have Wico Mag's. I've always worked on the more modern points, condensor and coil engines and I am new to magneto's. The parts for mags are much more expensive and I hate to spend more than I need. The first one I started working on hadn't been started for many years. I cleaned the carb and gas tank and checked for a spark. I had a spark but not sure how hot is was. I put a little gas in the cylinder and it didn't fire. I suspect a weak spark but hate to just start putting in coils, condensers and points or what ever else a mag needs. Is there a way to diagnose a problem with a magneto?