Without a schematic in front of me, sounds like the score motor is not resting in the proper place between revolutions since it is all of the kick-outs. OR, the switch on the motor in series with the kick-outs and out-hole relays is barely making when it should not be. Easy enough to find without a schematic by raising the playfield and hitting the outhole switch while watching the score motor turn. The kickout hole switch will make towards the end of the motor rev and will probably exhibit a minor arch as the outhole energizes.

I agree with Boatcat, the first thing I would check are the score motor switches.

Check the switch stack at motor 4C, these are almost always used for generating kick-out hole pulses. With the score motor in the home (at-rest) position, you may find one or more switches at 4C that are closed but should be open.

- TimMe

Regarding kickout hole strength, I find the coils at the top to be a bit aggressive. They fling the ball a little too hard, resulting in excessive playfield wear and/or whacking into the pop bodies and skirts.

I have restored two 2001 machines and the following recipe works very well:

Unwind 18 feet of wire from each pop bumper coil.
Unwind 18 feet of wire from each top slingshot coil.
Wind 36 feet of wire onto each kickout coil at the top.

This will give you livelier action at the top and reduce the kickout hole strength enough to save your playfield and pops.

I don't recommend unwinding the lower slings. They're peppy enough as-is. Otherwise you won't get to catch the ball enough.