A friend of mine has a 05 WR 450 that will start and run with the choke on, but as soon as you close the choke the bike quits. The bike is stock with the exception of a FMF Factory 4 Slip on. The carb is different than i am used to. There is no fuel screw and from what i have been able to read has something called a starter jet? I checked the needle, it is on the 4th notch. Main seems to be real lean with a 150. From what i have read, should be a 165. I could use some help from those of you that may be able to help. The bike has had none of the mods done.