COLD
It could be just cold blooded...as soon as you get the bike started remove the choke as soon as it will run on its own aafter you rev it up to clear the cylinders of the gas in them...running on the choke will cause it to run cold and also foul out the plugs and carbon things up...Another thing to check is that you are running the proper oil...try a 10-40 synthetic...and check your spark plugs to be sure that they are the right ones for your bike...if you are off by just one heat range it could do the same thing, run to cool. IF you were racing...then you might want to go to a cooler plug...but I don't think that this is the case...