Where is the scooter engine noisy?

[DeValerie]

The increased noise in a scooter engine may be due to faults in the air filter, exhaust system, or component gaps. Below is an analysis of the possible causes of scooter engine noise issues: 1. Air Filter: If the air filter's sealing performance deteriorates, the noise from the scooter will increase. This is mainly because the reduced air flow resistance leads to more noticeable noise. 2. Exhaust System: The exhaust system of a scooter is relatively simple, but if its sealing or noise reduction capability declines, the scooter's noise will also increase. 3. Component Gaps: Excessive valve clearance, loose timing chain, or excessive wear in the piston rings and cylinder block can all cause the engine noise to become louder.