[Al Skierkiewicz]

Triga,
The FP motors have a smaller terminal than that used for other electrical connections on the robot. I believe they are 3/16" instead of the 1/4" used for other devices like the Spike. Soldering is recommended to keep the terminals or wiring in place but it requires an experienced person to do so. The FP (and other motors) have an internal thermal circuit breaker. In the FP motor, this protection device is connected directly to the terminals. Soldering can pull this assembly out of alignment inside the motor and make it fail.
We use a flag terminal of the proper size, soldered to the end of the motor wire. Then after scraping the motor terminal to remove the protective film, we push the terminal into place and solder the terminal to the motor. We follow this with a piece of heatshrink tubing and then bend the wires down along the side of the motor and using a wire tie, secure them in place. Any tug or vibration on the motor wire is likely to fatigue the motor terminal without this secondary strain relief.