Saving Old Seagulls

I have a 1977 40 plus with a villers carb. I changed the needle for 25:1 and everthing works great except the rich lean screw keeps backing out. Should I put some loctite on it? How do it get it to stay in place?

Thanks!
-Tom

Is it possible that the taper needle spring wasn’t put back with the new needle? I believe that keeps tension on the needle threads to stop exactly what you are experiencing. Part number V107X7 in the Villiers carb diagram.

Thanks...I will have to check.