Salty25,
I've had my Rascal 40 for a year now. Over 100 flights. Mine broke exactly as yours did. I replaced mine with steel instead of aluminum.

I also check the engine mounting bolts before the first flight of the day. Mine seem to have a tendency to become loose. I expect the vibration from a loose mount is what is breaking them.

This is the first plane I've had with wood beam mounts. Perhaps as the wood looses moisture they shrink?" All I know is the last 50 or so flight have been fine - no broken mounts, and seldom are the mounting bolts loose.

The Rascal is a fine Sunday Flier.
John