[embee]

Sounds like it's pretty normal from what you say. Use full choke and DON'T TOUCH THE THROTTLE. This is most important, the choke (or strictly the cold start enrichment circuits) is engineered to give the right balance of extra air and enriched fuel to get it to start and fast idle with the throttle closed, if you move the throttle at all it can upset this and I find it can then be a pig to start.

My curvey always fires straight up but like you say it will very often stall after a couple of seconds. Don't alter the choke and don't touch the throttle, just press the starter again and it will 99% of the time fire up and run just fine.

Ease the choke off gradually as soon as you can while maintaining a smooth fast idle. Don't leave the bike idling for prolonged periods to warm up, just start it, let it settle while easing the choke down a bit for say 30sec at most then ride off gently. Get the choke off fully as soon as it is happy to run without it.

Super grade fuel often helps a bit with cold starting due to the mix of ingredients, iridium plugs help a lot too (need less voltage to spark and give better ignitability of lean mixtures). If you get carb icing at all, add 2% iso-propyl alcohol to the fuel (IPA - available on ebay - basically the main ingredienty of stuff like Silkolene Pro FST and much cheaper).