Flipper rebuild step 1: remove and check the coil stop

Steps

• Undo the coil stop's pair of Allen bolts (10-32 x 3/8 inch) and slide the coil out of the way.
• If the stop's face has mushroomed, replace it. Filing it flat lengthens plunger travel, which can wreck the top coil bracket or let the pawl hang on the EOS switch.
• Use coil stop A-12390 on later games and A-12111 on early WPC (and System 11) games; A-12390 in an early game reduces flipper travel.

Systems

• WPC Alpha-Numeric
• WPC Dot Matrix
• WPC Fliptronics
• WPC DCS
• WPC-Security (WPC-S)
• WPC-95

Related tips

• Coil sleeves and flipper rebuild spares
• Removing and checking the flipper coil stop
• Flipper rebuild part numbers for System 11
• Converting System 3-7 flippers to WPC-style mechanisms: main parts
• Flipper rebuild steps 8-9: correct coil, new sleeve, reassemble
• Flipper rebuild step 13: set flipper travel to 2 3/8 inch
• Mount the flipper coil with its lugs away from the coil stop
• Flipper rebuild step 5: replace the nylon playfield bushings

Source: Repairing Williams/Bally WPC Pinball Games from 1990 to 1999, Part Three, Clay Harrell (pinrepair.com)