What Causes Abnormal Noises in Motorcycles?

[JulianDella]

Motorcycle abnormal noises can be caused by the following reasons: Air leakage sound: If the fastening bolts between the cylinder and cylinder head, cylinder and crankcase, or left and right crankcases become loose or the gasket is damaged, a "squeaking" air leakage sound will occur. This sound is difficult to hear clearly when running at a constant speed after starting. During a stationary inspection, obvious oil traces can be found at the leakage point. If the issue is not severe, simply tightening the fastening bolts may resolve it. In severe cases, the gasket should be replaced. Valve knocking sound: If the valve clearance becomes too large due to improper adjustment or part wear, the valve mechanism will produce short and sharp knocking sounds. This knocking does not vary with changes in engine speed. It can be eliminated by adjusting the valve clearance or replacing worn parts.