Mag. Check

[Dale Campbell]

I just had a wire problem checking left magneto on front engine. When I check mags. before take off, I did not get a 100 RPM drop like normal, when I switched to left-right mag and back to both. The engine seemed normal other than that. I checked the rear and I did get normal 100 RPM drop. I than checked the front engine again. Then I remembered how the magneto works. You have to short a mag to get it to stop firing. I than pulled the front engine to idle and turned off the ignition. Guess what it keep on running.
I went back to the hanger and pulled the cowl and my suspicions
were right. The pig tail on the p-lead wire was broken, on the opposite mag I was checking, which is right. When you check left mag. you short out right mag. That could have cause a couple of problems. #1 if you pull a prop threw by hand, you could get killed. Thats why I always leave my mixture controls in full idle cut off position when parked or in hanger. #2 The other problem you could have is if you had a bad magnito, you would not even know it. So, make sure you see that drop in RPM when checking magnetos.