an old allen wrench works good also for the handle as well. there is a set screw on the needle to secure the wire.allen wench or what ever you want to stick in the hole.

Probably not the case but on competition scale stuff the norm is to drill and tap the needle and JB weld an allen head screw in and use an allen wrench to adjust the needle, this way you don't see it. Sound like it just a sport model so use the former