A Pachislo machine is the Japanese version of the American slot machine. According the website Slots.CD, the machines are legal in the United States for recreational use and are referred to as “skill stop,” meaning the player determines the location the reels stop, as opposed to the randomness of American slots. The recreational machines sold in the U.S. use tokens rather than money.
Open the Pachislo machine and locate the coin mechanism on the door. This is the only portion of the Pachislo machine that will need to be modified. Disconnect the wiring of the coin mechanism by pulling the plugs apart.
Lift the latch to open the coin mechanism and pull the mechanism toward you and slide it to the left to remove it from the door.
Locate the optical sensor -- this is the device that checks the size of the coin and is located in the coin path of the coin mechanism. Use a sharp knife to scrape the bottom of the sensor assembly so that the box will fit lower in the coin mechanism when returned.
Remove a small bit of material and reassemble the coin mechanism, then test-fit a quarter. Repeat the process of removing small amounts of material until the quarter is accepted by the mechanism.
Reassemble the coin mechanism and reconnect it into the Pachislo machine and you have a Japanese slot machine that accepts American quarters.