Hello, I wanted to see if I could get some data as I have a similar situation. I just got a 2003 DRZ400s and it has about 300 miles on it. I live in Los Angeles and will be riding from Gorman to Big Bear. Pretty wide range of elevations. What do you recomend I do as far as jetting. Acutally what does jetting mean, is it something I can do myself with a kit. I am auto mechanically inclined, never worked on bikes though.