Hi need some HELP! . My 400 foreman started losing power then just stopped? tried to start it but would run rough only a half throttle ? limped it to workshop had carb off . Cleaned no change . drained tank new petrol no change. checked timing / valve clearance all o.k. I even put a new carb on still the same :icon_frown::icon_frown: Runs rough at half throttle . if you open throttle more just stops the same? had exhaust of too just to see if it was a back pressure problem . it,s driving me mad:confused::confused: