The flippers feel weak and only sometimes get the ball up through the spinners, even after a rebuild with all new parts except the coils.

Flippers still weak after a rebuild kit: clean the new EOS contacts

Cause: The end-of-stroke switches were opening too early or not making good contact, even though they were new.

Checks

• Check that each EOS switch is firmly closed at rest and only opens at the very end of the stroke.
• Clean the EOS and cabinet flipper switch contacts.
• Make sure the bat moves freely with no binding.

Fix

• Clean and adjust the EOS contacts so they make firm contact at rest and open only at full stroke.

EM flipper circuits carry live voltage at the switches; switch the game off before adjusting contacts.

Systems

• Electro-mechanical

Games

• Night Rider (EM)

Related tips

• Flipper still weak after a rebuild: wiring and contacts
• Zipper flipper rebuild parts and stronger coils
• Weak flipper from an over-tight return spring
• How an EM flipper coil and its EOS switch work
• Gottlieb EM flipper rebuild parts
• Rebuild EM flippers before fitting stronger coils
• Flipper EOS switch: gap, checking and cleaning
• Weak flippers on an EM: adjust the end-of-stroke switch before buying coils

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