hey guys new here and first post so this may have been talked about in the past.just got my son a new 2021 kx 85 about 6 months ago and he have a a lot of woods behind are houses and a big sand pit with a lot of free riding and hills and trails.hes a animal on this thing and is wanting to do upgrades from Santa as hes already banging through the gears and sending it like Ricky bobby.looking at maybe a full exhaust and a v-force 3 reed cage along with a better flowing filter.what exhaust is a good all around power set up with out loosing power in one area.my son is 11years old on the short side and is 83 pounds in his pjs fresh out the shower with no shirt on..lol.