Yeah what stupid said works. :nana:Depending on how cold it is outside, I'll typically run it on full or partial choke for about 30 seconds to a minute.
A mechanic once told me that you should modulate the choke so that the bike keeps around 1500. If you leave it on for too long it runs rich and fouls your plugs. I don't believ it would foul your plugs, but if you're starting in the cold, your oil is gonna be really thick, so I just assume running at a lower RPM would probably keep your engine from wearing as much. But IDK for sure, just my two cents