Removing the speed limiter on a Yamaha TW125 involves modifying the bike's CDI (capacitor discharge ignition) or adjusting the throttle stop screw, if applicable. However, it's important to note that tampering with the speed limiter can be illegal and unsafe, potentially voiding warranties and violating local regulations. Always check local laws and consider the safety implications before making such modifications. Consult a professional mechanic for guidance if unsure.