Which lubricant to use on an EM
Use a Teflon gel (Super Lube, 3 oz gel tube 21030); it does not dry out. 3-in-1 style oil works only for a while before drying and going gummy, and white lithium grease dries up within about a year and makes a mess.
Systems
Related tips
Source: Repairing Electro-Mechanical (EM) Coin Operated Games to 1978, Part One, Clay Harrell (pinrepair.com)