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#3: Plane was purchased used and brought to Randy for an annual inspection.
What's wrong with this motor mount? (scroll down for answer)
Holes were drilled in motor mount. Note in forth picture the JB Weld that was used to fill two holes. The inside of the steel tubes used in motor mounts will rust/corrode when exposed to moisture, and any holes drilled in it not only weakens the structure considerably, but allows corrosion to take hold. Washing the plane and flying through rain speeds the process. Randy has seen old ag spray planes with holes in the mount that were corroded so bad you could bend the steel with your hands.
Bottom line: Don't drill into the motor mount.
An expensive fix, though less expensive than having the engine depart the aircraft in flight. Engine has to be pulled and the mount repaired at a facility (like McCutcheon Metal Fabrication for example) that works on aircraft motor mounts. All the braces that had holes in them had to be cut out and replaced. Photos below taken during and after repair (and before powdercoating). Randy Richmond photos.
photo courtesy: http://mccutcheonmetalfabricationaviation.com