Hey 99tjrockcrawler... I ride dunes all the time on my 5, and one thing nobody touched on is the fact that you are bogging in 4th... my bike never boggs, even in 5th, unless I miss-shift and hit a gear too early. I think there may be something wrong with your bike like jetting, lack of compression or something. I've never had the opportunity to drag race a new 4stroke (they seem to all go the other direction when I come around on the green beast) but I do know that this bike which is all stock with FMF pipe and silencer and a sand snake 10-cup paddle, has more nuts than I know what to do with and never boggs unless its because of rider error. Just wanted to point that out since nobody else touched on it.