I've had trouble keeping the muffler mounting bolts on my Moki 1.80 tight. More then one occasion the bolts holding the muff on have loosened, and even lost one one time.
It's a Brison pitts style, very common for the engines, used by most from what I understand, and up until I put it in this plane, I had no trouble. It's in my Hanger9 Edge, stock mount for the engine.
I would use loc-tite, however, I've seen what that can do to aluminum, and am leary to have anything more happen to the mounting holes.
I'm thinking I'm going to get some lock-washers(metric, to fit exact).
Maybe I'm not tightening them enough, however, again, with aluminum(even the good stuff that engine is made of), I'm just very leary of damaging those holes. I'm pretty good at judging torque, and knowing when tight should be tight enough, however...it does seem, I can't get it tight enough.

Does anyone have any input, suggestions, or experienced the same thing??
Thanks guys!!