Will a tx3 motor fit into a 85 kc laser. is the difference. will it be faster of what?

A TX3 motor will not directly fit into an '85 KC Laser without significant modifications, as the mounting points and dimensions may differ. If successfully installed, the TX3 motor could potentially offer improved performance depending on its specifications compared to the original motor. However, factors like weight, drivetrain compatibility, and tuning would also impact overall speed and performance. Always consult with a professional before making significant modifications to ensure safety and compatibility.