2. Re-jet the carburetor. The carburetor controls the amount of fuel and air that is mixed together and sent to the engine. By re-jetting the carburetor, you can change the fuel-to-air ratio, which can improve low-end power. Re-jetting the carburetor is a more complex modification than installing a slip-on exhaust, but it can also be more effective.
3. Install a larger air filter. A larger air filter will allow more air to flow into the engine, which can improve low-end power. However, increasing the size of the air filter may also require re-jetting the carburetor.
4. Install a higher-compression piston. A higher-compression piston will increase the compression ratio of the engine, which can result in more power. However, installing a higher-compression piston is a major modification that should only be done by a qualified mechanic.