What was found
AFTER FLIGHT, ENGINE WOULD NOT START. BOTH MAGNETOS FOUND TO BE INOPERATIVE, NO SPARK. IT HAS BEEN FOUND THAT ONE MAG GOES INOP. ENGINE STARTS ON THE GOOD ONE, UNTIL IT FAILS. AFTER THE ENGINE RPM MEETS OR EXCEEDS 600 RPM, THESE COILS WILL MAG CHECK OK. INSTALLED FACTORY NEW COILS, PN M3975. OPS SATISFACTORY.