I have a 98 YZ400 that I bought new back in 98. I have to say this bike has been amazing. Over 10,000 miles and not one problem with the engine or transmission. Been very low maintanance. Haven't ridi'n it in quite sometime and I think it's in need of a jetting change and carb cleaning. I can't get it started and if it does start it runs terrible. Very hard to start. This bike is stock and has had no mods to it. Just wondering what I can do to get it going again. What kinda carb is on a YZ400? I would like to start out by changing the pilot jet and main jet. What sizes should I use. I'm in the AZ desert ride in about 70 degree temps and elevation is between 500 and 1000ft. I'd appreicate any feedback. Thanks.