Depending on the type of electric pto clutch it would be out of adjustment. If the clutch is triangle shaped with a stud, spring and nut on each corner than I would try adjusting the air gap. Next to each spring there will be a slot to insert a feeler gauge. You wand to insert a .012-.016 feeler gauge between the two disc inside the slot and adjust each nut to achieve that clearance on all three corners and see what happens.