As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE NR 4 CYLINDER EXHAUST RISER PULLED OUT OF THE MUFFLER DURING TAKE-OFF RESULTING IN SMOKE IN THE COCKPIT.INSULATION MELTED AT THE STARTER CONTACTOR AND PLACE WHERE MAIN WIRING HARNESS PASSES THROUGH THE FIRE WALL.NO FAILURE OF THE CLAMP OR HARDWARE WAS NOTED.