The hanging seems to be fixed now; somehow. I started and ran the bike this morning; allowing it to warm up before I used a strobe light to set the timing. Timing was out by a few degrees - in front of the F mark so retarded? Since I posted I had a hanging problem I have stripped and cleaned the carbs; replaced the old idle jets with 'new' Honda ones, re-set the float heights to 22mm; 2 were way out and re-synched the carbs on the bench so the slides are just opening. Before I bench-synched with a small gap using a drill bit as a gap tool. I have also fitted 2 in-line Aeroline fuel filters. Idle air screw is out 1.5 turns on all 4 carbs.
Another thing I noticed when starting the bike this morning was that when I turned the fuel tap on there was an audible release of air pressure. I also got this when I opened the fuel cap to check the fuel level in the tank. I have an aftermarket fuel cap from DS and when I checked the vent hole I found that a piece of cotton wool or similar was pushed into the little vent hole; presumably to prevent ingress of dirt. However, it was so tightly pushed in that it was preventing the air from getting in the tank so I removed it.
I don't seem to have any hanging issues now and the plugs which were super sooty are now a nice tan colour with no oil or soot.
The remaining issue is that the bike is not eager to pull away from standstill and needs more revs than I think it should. Im going to be investigating this next but if anyone has any pointers for this issue please point!
