If you are experiencing a "tuck" sound when downshifting your Pulsar 200 NS motorcycle, it could indicate a potential issue with the bike's transmission or clutch. Here are a few possible causes:
Clutch Adjustment: Improper clutch adjustment can result in the clutch not disengaging fully when you release it, leading to a "tuck" sound. Check if your clutch cable is properly adjusted, ensuring that there is sufficient play in the cable and the clutch is fully disengaged when you pull the lever.
Worn Clutch Components: Over time, the clutch plates, springs, or other components may wear out, causing a lack of smooth engagement and resulting in the noise you're hearing. A worn clutch may need to be replaced to restore smooth shifting.
Transmission Issues: The noise could also be related to transmission problems, such as worn gears or synchronizers. These issues can affect the smoothness of shifting, especially during downshifts. A qualified mechanic should inspect the transmission to identify any potential problems.
Engine Oil: Ensure that you are using the correct type and grade of engine oil recommended by the manufacturer. Insufficient or improper oil can affect the clutch's performance and cause unusual noises during shifting.
To address this issue, I recommend taking your Pulsar 200 NS to a trusted mechanic or a Bajaj service center. They will be able to diagnose the problem accurately and provide the necessary repairs or adjustments to ensure smooth shifting and optimal performance of your motorcycle.