All your bolts are tight but the inserts are loose? Is that what you just said? You're facked if that's the case.
Those bevel head Allen key bolts are short. Like 1/2 inch long thread depth. They are stainless into aluminum blocks so torque is critical.
I ride my ski 3-4 days a week and have had my engine plates off half a dozen times.
If it's just loose take it apart. Clean the mounts with brake clean and vacuum the holes out. Clean off the bolts with a wire brush, and use red loctite to reinstall. Don't over torque them. I thrash the sh it out of my ski and they have never gotten loose.
