Finally getting around to jetting my 03 WR450 (Canadian model). Been researching which jets to change. I noticed that the JD kit comes with a few main jets and some needles only. Their website doesn't appear to list the size of the main jets. Should I order specific sizes from an OEM parts store, or buy the kit and an adjustable feul screw? And which store is a good source for the seperate parts? Most of my riding is 1000 to 7000 feet, 50 - 80 degs F. Thanks.