How can you make a Yamaha 650 louder?

To make a Yamaha 650 louder, you can replace the stock exhaust with an aftermarket performance exhaust system designed for increased sound and flow. Additionally, removing or modifying the baffles in the existing exhaust can enhance sound volume. Installing a high-performance air filter can also improve overall engine performance, which may contribute to a louder exhaust note. However, be mindful of local noise regulations and the impact on performance and emissions.