I think Richard hit the nail on the head. I've sold lots of dirtbikes, race quads and motorcycles (all of which had lots of hop-ups) and you never get even close to what you put in them. In fact, lots of buyers prefer stock bikes...especially bikes w/ no engine mods (we build the motors to ride them harder, right?). Never stopped me from building my motors, never will.....it's just what I do.