Hi gents, sorry to hear some of you are struggling still with your bikes, I hope my post has been a little helpful - if not just use it as a work flow to check off the things that could have an affect.
I've since found mine to be absolutely amazing, after routing out the bad wiring (left as a present by a previous owner) it's dependable and reliable. I changed the regulator and battery recently as I did a quick check on the battery voltage when running and found it to be 18v, I took the opportunity to fit a Yuasa battery and she usually starts first hit on the button now - hot or cold.
I've been racing recently on a 2 stroke KTM, the gasser a bit heavy but great for green lanes with the old man - I might just end up keeping it