Hoover 1300 Logic A3636 erratic speed?

My old Hoover 1300 Logic A3636 works fine except that it has started bouncing around when it begins wash cycle. Water comes on, heat starts and the drum should slowly rotate but sometimes it goes into a mini spin. Sometimes for a fraction of a second you can hear the motor do a spurt of speed before returning to normal. Result is unbalanced wet load is throw suddenly from side to side. Then machine settles down and completes wash spinning smoothly.