What Causes Abnormal Noises in Motorcycle Power?

[McLeila]

Motorcycle power produces abnormal noises due to excessive clearance and severe wear. Below are the relevant explanations: Excessive Clearance: The piston knocking sound is usually caused by excessive clearance between the piston and the cylinder. During the engine's power stroke, the piston is subjected to high-pressure gas, resulting in noise. Severe Wear: When the big-end bearing of the connecting rod is severely worn (or loose), there is a noticeable noise during engine idling, which intensifies under increased load. Sudden acceleration (from idle to medium speed) produces a distinct continuous knocking sound (rolling bearings may also cause internal engine noise), which is the main characteristic of big-end bearing noise.