For the Royal Enfield Classic 350, it is recommended to change the air filter at regular intervals to ensure optimal performance and engine health. The specific interval for air filter replacement can vary depending on various factors such as riding conditions, air quality, and maintenance practices. However, as a general guideline, it is advisable to replace the air filter every 3,000 to 5,000 kilometers (or approximately 1,800 to 3,000 miles) or every six months, whichever comes first.
It's important to note that if you frequently ride in dusty or off-road conditions, you may need to change the air filter more frequently. Additionally, if you notice a significant decrease in engine performance or if the air filter appears excessively dirty or clogged, it's a good idea to replace it even if it hasn't reached the recommended interval.
Always refer to the Royal Enfield owner's manual or consult with a qualified technician for the specific maintenance recommendations for your motorcycle model, as they can provide the most accurate guidance based on your specific circumstances.