So here's the story....

I have 7 flights on my plane In the first 3 flights I had to re tighten and locktite everything around the engine. Now after the 7th flight I have allot of the same bolts loose.

Now I think I figured out that the 1/4" plywood spacers that I had are compressing and allowing the mount bolts to loosen. I am going to use 1/4" aluminum spacers instead. This should hopfully solve that issue.

Now all you guys that are having no issues with this, what have you done to keep this type of thing from being an issue?