the YZ250 is like having a hand grenade in your hand with the pin pulled, when it comes onto pipe the torque thrust is nothing that you can imagine, its like if you had a turbo on your 4 stroker and hit nitrous at the same time as the turbo spooled up.
YZ is in its game on loose sand, the tire digs in - gives just the right load to force the engine to come onto and remain on pipe.