Angle the topslide of your lathe and bore a tapered hole, while its at the same setting also turn the taper on the shaft or collet if it has one then they will match perfectly.
Thats also quite a small hole to get a bar into though it can be done you may find it easier when turning the male part to then turn a matching taper on a piece of silversteel and make a "d bit" type reamer by milling/filing half th ewidth away, hardening and then feeding it into a 4mm hole in the flywheel
J
Edited By JasonB on 24/06/2014 10:28:13
Edited By JasonB on 24/06/2014 10:28:57