With one ball the outhole kicker works, but when two or three balls land in the outhole at once it cannot push them into the trough.

Outhole kicker struggles when two or three balls drain together

Cause: A sluggish kicker mechanism, usually a dirty pivot and a worn coil sleeve, even when the mech seems to move freely by hand.

Checks

• Confirm the correct coil is fitted (the owner had the AE-27-1200 specified for this game).
• Remove the apron and check the mechanism and pivot for dirt or drag.
• Look for a swollen coil that grips the sleeve.

Fix

• Take the mechanism apart, clean the pivot and plunger, and fit a new coil sleeve.
• Replace the coil too if its former is swollen.

Systems

• WPC Fliptronics

Games

• Twilight Zone

Related tips

• Multiball drain stays in the outhole while more balls are served: stuck trough actuator
• Old and new WPC ball trough designs
• After a power cut: resets, then won't serve a ball
• Twilight Zone trough proximity sensor (switch 26) problems

Source: Pinball Repair help group!! (Facebook group)