I have bayonet-style engine mounts, and discovered that one of the underside nuts had vibrated itself loose. The same thing happened a few years ago, and I put an electric tie tightly around the stud up against the nut. It held for a few years, but apparently the tie weakened over time.
I tightened the nut back up, and this time I ran an electrical tie underneath the nut, and diagonally up and over the engine mounting bracket. It seems like this should prevent the nut working itself loose again, but there must be better ways to do this. On my forward engine mounts I have twin nuts on both the top and bottom sides of the stud to act as locking nuts, but on the aft mounts there is only room for the one nut on the underside of the mount.
I've considered putting a narrow hose clamp around the stud just below the nut, as an improvement over the electrical tie. But again, none of these solutions seems optimal.
I don't want to use Loktote because you need to be able to tweak the nut when aligning the engine.
Thanks for any other ideas that folks have used.
Max