I'm looking to move up from my XR250 to something that is a little more track friendly. Most of my riding is on trails but my son likes to ride tracks once an a while. When I follow him around the track my XR250 is a dog. I think a WRF426 might be the next logical step to take. The pure MX bikes seem to require a lot of maintenance compared to my XR250. Does a WRF require the same amount or frequency of maintenance as a YZF? Can a 6'3" 210 person have fun (not race) on a MX track with a WRF 426? Do all WRF's have a spark arrester?