8780-4 Lock nuts tappet adjuster screw

These Colony lock nuts for tappet adjuster screws are an essential component for any vintage Harley-Davidson engine builder. Featuring a 9/32-32 thread, these nuts are a direct replacement for OEM number 18570-38. They fit a wide range of models from 1915 to 1985, covering everything from early Flatheads and Knuckleheads to Panheads and Shovelheads, though they are not for Evolution Big Twin models. These nuts are critical for securing your valve adjustments and preventing them from backing out under the intense vibration of a running motor. This set includes four nuts, providing a complete solution for your tappet assembly with the reliability and precision Colony is known for. They are a must-have for maintaining accurate valve timing on classic machines.