I just wanted to thank all the people and input I received for the year long build up of my 98' YZ400F. It runs like a stripped a$$ ape! WOW! I have always owned and ridden 2 strokes. Never again. The only issues that I'm having now are a small backfire after I let of the throttle, a drop or two of oil out of the breather tube from the head and I'm not sure how hot the head should feel after a short ride. All of my rides have been about 10 min. or less. I also can't seem to get it to idle very well. Sorry such vague info. The bike does run very well. I'm just taking it easy for about the first hour then I will change the oil and start to do more fine tuning. The jetting looked like stock numbers when I had it apart the other night. The only thing I did was clean it and back out the fuel mixture screw two turns. Thanks for your help. What a blast!