Hi
I thought that I'd share a bit of knowledge with my fellow sunbeam riders incase someone was in a similar situation as I was a while back. The Kickstart on my burman box snapped under use and was found to have weld porosity / corrosion from an older repair that wasn't visible due to the previous owners dressing of the weld and subsequent re-chroming etc.
I haven't yet repaired the original kick start, but have fitted one from a BSA B40 as the dimensions match that of the burman shaft and can be fitted without any modification required. It is additionally longer than the original and therefore makes kickstarting the bike easier!
I hope that this bit of trivia helps any other sunbeam owner who is struggling to find a replacement part
Jim