Check bolts not a bad idea.
I noticed that the 2 M6 bolts holding the front drive sprocket were almost gone on my K6 some years ago.
1 had left, the other not many turns left.
After that Loctite 222 (purple) which is a weak locker but will not let bolts and nuts to move on their own. Easy to remove with tools.
I use it on front rotors, caliper brackets to fork, rear sprocket nuts, nuts holding exhaust, rear foot pegs, front wheel M8 nuts etc.
Cam sprocket bolts get medium strenght (blue).
All threads cleaned with acetone before Loctite.