The idle engine RPM for the Yamaha R15 V2.0 is typically set to around 1200-1400 RPM (Revolutions Per Minute). However, it's important to note that the exact idle RPM may vary slightly depending on factors such as the specific model, local regulations, and personal preferences of the rider. It's always recommended to consult the owner's manual or contact a Yamaha authorized service center for precise information on the recommended idle RPM for your specific motorcycle.