Purchased last spring a 2001 mojave w/ straight pipe (no restriction at all) exhaust and just added a k&n. Main jet has been changed to 2 sizes higher than stock. I live in MN, and if its under 32 degrees, forget about getting it started without kicking for an hour. Are these known for being cold blooded? The spark plug was replaced last April, do these foul many/frequently?

 

Are you sure your choke is closing???
Check it next time it is running and warmed up and then push choke full on and see if it stalls engine

 

Choke turning on does kill engine when running. I may just have to keep it in heated garage for winter or early spring riding here in MN

 

You could try blocking the air intake, to richen it up, when starting cold. Put a piece of duk take, or even your hand, over the intake, and cover it up, about 80%. That should help the enrichener, get the mixture rich enough to fire.
Could also try going out a 1/4 or 1/2 turn on the mixture screw, usually that isnt enough to cause drivablity problems, but will richen up the idle.
Could also try holding the throttle@1/4 open during cranking, then the midrange jets are working, and that should richen things up.
let us know if this helps.