Bike wants to die when throttle used?

[falken231]

I have a 2000 yamaha 4 stroke dirt bike and when i first start it with the choke it will fire up great, but as soon as i give it even just a little bit of throttle it wants to die. If i let it sit there and idle with the choke for about 5 straight minutes it seems to work itself out but ive bikes in the past that never did this. What could i do to fix this?

 

[BobB]

its common when its cold out with the four strokes. I actually just started my 02 Yamaha yz450f and had to the same thing