If your Honda CB750S motorcycle is making a sound similar to a card stuck in the spokes, it could indicate an issue with the engine or other mechanical components. There are several possible causes for such a sound, including:
Valve Train Issues: The sound could be related to a valve train problem, such as a worn or damaged valve or a loose valve shim. If the valves are not opening and closing properly, it can create unusual noises.
Engine Timing: Incorrect engine timing, such as a misaligned camshaft or a timing chain that has jumped teeth, can cause abnormal sounds in the engine.
Exhaust System Issues: A loose or damaged exhaust system component, such as a heat shield or baffles, can create rattling or buzzing noises that may resemble a card stuck in the spokes.
Loose or Worn Components: Loose or worn-out components, such as a loose engine cover, bolts, or brackets, can vibrate and produce unusual noises.
Clutch or Transmission Issues: Problems with the clutch or transmission, such as worn-out clutch plates or damaged gears, can cause unusual sounds during idle and at speed.
It is recommended to have your motorcycle inspected by a qualified mechanic or Honda dealership to diagnose and address the specific issue causing the unusual noise. They will be able to perform a thorough examination of the engine, transmission, and exhaust system, and make any necessary repairs or adjustments to resolve the problem.
It's important not to ignore unusual noises in your motorcycle, as they can indicate underlying issues that may worsen if left unaddressed. Prompt attention and professional diagnosis will help ensure the optimal performance and reliability of your Honda CB750S.