The paint streaks or color markers on engine bolts of new motorcycles serve as a visual indication to identify whether the bolts have been tampered with or loosened. These markings are often referred to as torque paint or torque seal.
Here are a few reasons why manufacturers apply paint streaks or color markers to engine bolts:
Quality control: The markings provide a quick visual check during the manufacturing process to ensure that all bolts are properly torqued to the recommended specifications. By applying torque paint, it becomes easier to identify if any bolts have become loose or have been tampered with during production.
Assembly verification: The paint streaks help the assembly line workers or technicians quickly identify if all the required bolts have been properly tightened during the assembly process. This helps prevent missing or loose bolts that could potentially lead to safety issues or component failures.
Service and maintenance checks: The color markers can assist mechanics or service technicians in identifying whether bolts have been loosened or tampered with during any service or maintenance work. If the paint streaks are intact, it indicates that the bolts have not been disturbed. However, if the paint is broken or missing, it could suggest that the bolts have been manipulated or require inspection.
By using these visual markers, manufacturers and service professionals can easily identify any potential issues with bolt tightness, ensuring the overall safety and reliability of the motorcycle. It's important to note that these paint markings should not be removed unless necessary, as they serve as an important indicator during maintenance and inspection processes.