As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING THE PRE-TAKE OFF RUN UP, THE RIGHT MAGNETO HAD NO SPARK AND THE ENGINE WOULD QUIT WHEN THAT MAGNETO WAS SELECTED. THE AIRCRAFT RETURNED TO THE RAMP. INVESTIGATION REVEALED THAT THE IMPULSE COUPLING, SLICK HAD FAILED AND PIECES OF ONE FLYWEIGHT AND SHAFT ASSEMBLY WERE FOUND AS METAL PARTICLES IN THE ACCESSORY CASE MOUNTING PAD AREA AS WELL AS THE INTERNAL MAGNETO FLANGE AREA. SOME OF THE METAL WAS ALUMINUM, WHILE OTHERS WERE FERROUS. THE ENGINE IS SCHEDULED TO BE CHANGED.