What are the reasons for a motorcycle making abnormal noises at low speeds but not at high speeds?
1 Answers
The reasons for a motorcycle making abnormal noises at low speeds but not at high speeds are as follows: 1. Insufficient or deteriorated engine oil. 2. Normal wear and aging of engine components. 3. Frequent improper operation or high-speed riding causing engine damage. Extension: Classification of motorcycle abnormal noises: 1. Knocking caused by detonation: When the engine suddenly accelerates or the motorcycle is going uphill, a continuous sharp "tapping" sound from inside the cylinder is knocking caused by detonation. 2. Air leakage sound: If the fastening bolts are loose or the gaskets are damaged between the cylinder and cylinder head, cylinder and crankcase, or left and right crankcases, a "squeaking" air leakage sound will occur. 3. Valve knocking sound: If the valve clearance becomes too large due to improper adjustment or part wear, the valve mechanism will produce a short and sharp knocking sound.