I put a timney on one of my MK V's a few years ago . if I remember right there were two different triggers listed . one for German built and one for Japan built . could this be your problem, the wrong trigger ? Jim
I got the safety to work by removing a couple of thousanths of the rear of the sear, per Timney's instructions. I had the correct US trigger for the US made Mark V.
Thanks for your responses. I will go the spring route with my other Mark V.