Hello I bought an 06 yz450, I currently have a 94 kx 250 (I'm sure it will be like night and day better) I've been lurking on the forums for a couple of years, and wasn't even sure if I was going to buy a four stroke, but this will be my first four banger I planned on getting a crf450 (which I'm sure I would be happy with) but decided to go with the yamaha thanks to all the good things I heard from you guys. (valve train, suspension, and so on) I've followed your guys recommendations, raised the forks, got a new front tire, a gytr air screw, jetting) I bought a 48 pilot jet (turned out the shop gave me the wrong one) and put in the 170 main. Should I bother even breaking it in tomorrow, temps will be in the upper 50's to 60 degrees. I've waited this long. I can wait another week. I'm concerned about riding it with the stock pilot jet. I want to do the right thing. (I'm a little nervous being my first four stroke) But I want to thank you guys for all the great info over the years.