ok, i have replaced the diaphragm and i must admit it did help a fair bit. The edger does not cut out once throttle is released and does seem to respond to being tuned now as well!

The only thing i am having trouble with atm is actually getting it to start up, does anyone know of an official startup procedure for this edger?
i manage to start it by:
1. priming half dozen times
2. turning over to full choke and pull the starter few times till edger burps
3. turn it over to half choke and half throttle and pull another half dozen times,
4. going back to choke (caus it never fully engages)
5. finally, after fiddling for a while i give up laugh
6. 5 mins later i pull away like a mad man on full throttle and no choke and it comes to life!