I'm happy enough to release the Iron horse back into the wild. Seems as though it is a common problem to be hard to start cold but run great when going. Being satisfied that the carby had no blockages etc the best I got to was about 4 pulls to start. I concluded that they just don't draw up enough fuel even with the choke butterfly securely closed. The choke butterfly has quite a large hole in it so decided to block this thinking it will improve the cold start or flood. Started first pull, then on repeat cold starts 2 pulls but if it didn't fire second pull, next pull resulted in flooding, I thought this was good as at least it was pulling up enough fuel. From here I adjusted the choke butterfly opening via the throttle cable in very small increments until I now have a very reliable 2 - 3 max pull cold start without any signs of flooding. Don't even think about starting them without the air filter and cover on ( unless you flood it ) they must be set very lean to meet emission standards, with the engine running at lower revs opening the air filter box results in engine surge. I tried giving the air filter a light oiling early in the staged of trying to improve things but felt it made no difference, it's quite a large thick foam filter. The other reason I think they are set lean is the amount of time it takes to run out of fuel once the tap is turned off, I thought the tap must have been leaking but it wasn't, they must be great on fuel consumption.
