Ok, went down to Kentucky this weekend and had a blast, hit things I didn't expect too. Hill from H**l, rocks, bolders, river beds... Yet, i was trying to keep up with CR 250's, and XR450's.. My XR400 was no match... Mods todate -- 1) Header welds ground out - 2) New air cleaner 3) Dropped one tooth on front sprocket.. Still have stock muffler and stock carb setup -- Seems to give out about 1/2 through a gear -- could be jetting (Others have suggested mods to it) ... I live in Central Indiana ---- Mostly flat land, yet I travel south and to Ohio alot.. Can you help..