The YZ125 is the only bike that actually terrified me from its acceleration. It doesnt surge - its snaps ahead. its like you are not moving to a new location you suddenly appear at the new location.
and a relative of mine in Karachi had this bike
175cc two cylinder, one head, one spark plug, second connecting rod bolted to first rod, transfer port in rear cylinder, exhaust port in front cylinder, both pistons did not rise and fall completely even, one followed the other a little later. talk about two stroke with torque