Do I have to replace the self-locking nuts on the engine mounting bolts?

[roedvigmads]

Hey Guys
I am currently rebuilding my engine, and I am installing the engine on saturday.
My question is:
Do I have to replace the self-locking nuts that sits on the engine mounting bolts?
Have a nice day

[prmas]

No, you do not have to.
Just add a drop of thread locker and tighten to specs. 

Macka

[lucas]

No, you do not have to.
Just add a drop of thread locker and tighten to specs. 

Macka

I did this.  It's been a month and the engine hasn't fallen out yet.

[sledge]

They can be reused several times. If you cant screw them up by hand they are very unlikely to loosen off in normal use.