1 small thing you can do, is with all the nuts and bolts that have extra thread protruding, cut off all the excess on everyone you can get to.
also, search on here for wiring harness, and cut it down to the bare minimum.
i saw an aluminum swinger on ebay a while back but it didnt specify if it was for drag only. it was gusseted pretty well but it would be iffy IMO for MX use...(it looked nice tho lol).
i think cascade has aluminum pegs? (check rocky mountain atv).
do you have to use plastics for MX? lol. if not , cutoff plastic supports.
light aluminum bumpers.
might be able to find aluminum lug nuts somewhere?
keep the gas level at a bare minimum when racing.
galfer type wave rotors have less material then stock disks.
ditch the parking brake BS.
use pod filters (the foam type are extremely light)
anyone know if the trinity single carb setup weighs less then duals? i would think the Graydon single setup weighs a tad less then trinity.
big money for some aluminum hubs.
ported jugs will help with power and minimal weight savings
i think that cool head type heads weigh less then stock does. (maybe, could be wrong about that)