What was found
LOSS OF 5 INCHES OF MP AT FL 240 AND INFLIGHT INVESTIGATION SHOWED A ROUGH RUNNING RH MAGNETO. DISCOVERY OF A DEFECTIVE SPARK PLUG LEAD (SEE OTHER SDR) ON A 25 HR TTSN CHAMPION SPARK PLUG HARNESS LED WITH 25 HRS TTSN SPARK CHAMPION RHB32E SPARK PLUGS LED US TO INVESTIGATION OF THE ASSOCIATED MAGNETO. DURING INSPECTION OF THE BLUE LABEL 25 HR TTSN (CMI REMANUFACTURED) S-1200 MAGNETO WE FOUND A LARGE CRACK IN THE DISTRIBUTOR GEAR. UPON MICROSCOPIC INSPECTION IT APPEARS TO BE A CASTING DEFECT. THE CRACK/DEFECT RADIATED ACROSS VIRTUALLY THE ENTIRE DIAMETER OF THE GEAR BUT WAS NOT IDENTIFIABLE IN THE GEAR TEETH. . WHILE THIS DEFECT WAS NOT RESPONSIBLE FOR THE LOSS OF MP IT SEEMS TO SHOW A LACK OF QUALITY CONTROL AT CMI IN THEIR MAGNETO/PART DEPARTMENT AS THIS GEAR SHOULD HAVE NEVER BEEN PLACED IN THE MAGNETO. (PHOTO AND MICROSCOPIC PHOTOS AVAILABLE).