Getting a popping sound from an aftermarket exhaust on a motorcycle is often associated with a rich fuel-air mixture and unburnt fuel igniting in the exhaust system. Please note that modifying the exhaust system may have legal implications and could also affect the performance and warranty of your motorcycle. If you still wish to pursue this, here are a few general suggestions:
Adjust Fuel-Air Mixture: A richer fuel mixture can increase the likelihood of producing popping sounds. However, it's important to note that excessively rich mixtures can lead to poor performance and engine damage. Consult an experienced motorcycle mechanic or tuner who can make appropriate adjustments to the fuel-air mixture using methods such as rejetting the carburetor or remapping the fuel injection system.
Install a Fuel Management System: Consider installing a fuel management system, such as a fuel controller or piggyback module, specifically designed for your motorcycle. These systems allow for more precise control over the fuel delivery, which can help achieve the desired popping sound while maintaining optimal performance.
Aftermarket Exhaust Design: Certain exhaust designs, such as those with less restrictive baffles or mufflers, may promote popping sounds to some extent. Research and select an aftermarket exhaust system that is known to produce the desired sound.
Exhaust System Modifications: If permitted by local regulations, you can modify the exhaust system by removing or modifying baffles, resonators, or other components. However, be aware that altering the exhaust system can affect the motorcycle's performance and may result in increased noise levels.
Professional Assistance: It is highly recommended to seek the help of experienced professionals or motorcycle tuners who specialize in exhaust modifications. They can offer guidance, make appropriate adjustments, and ensure that the modifications are performed safely and legally.
Remember, modifying the exhaust system may have consequences, including noise violations, reduced performance, and potential damage to the engine. Always consider the legal and technical implications before making any modifications to your motorcycle.