The springs wire used with that plastic vibration damper. Springs held the motor against the damper at idle to help keep it from shaking itself to death. Actually, more to help hold it still so it would idle. They did a lousy job of doing what they were supposed to do, and the motor shook very badly and idled poorly. And the plastic vibration damper lasted about two weeks if you were lucky.
Later on, they started using the vibration dampers on the sides of the powerhead, and they made a vast difference in smoothness and how it ran and idled. Finally, a motor that you could troll with.