With the goal of improving torque and acceleration on small-displacement, two-stroke scooters, the Vicenza-based company Athena, which specializes in high-performance motorcycle, scooter, and moped parts and accessories, has developed a brand new full-system exhaust designed for the vertical air-cooled Minarelli engines equipped with Athena's Big Bore kit.
Following the success of Athena's 70cc Big Bore cylinder kit for the tiny Yamaha-Minarelli Verticale engine, the company's R&D team has designed a new exhaust system that can be mounted on a variety of scooters powered by that engine, including the MBK Booster, Yamaha BW'S, and Aprilia SR, to name a few. The exhaust system is compatible with a wide range of vehicles; a comprehensive list may be found on Athena's website, which is linked below.
The manifold and expansion chamber are constructed by hand welding over 18 steel pieces with a thickness of 0.8 mm, and are designed to not only increase the scooter's power and torque figures, but also to offer improved durability over time, and sustain the temperature and physical loads encountered in a competitive environment. The Athena exhaust weights a total of 3 kg thanks to the carbon silencer. The entire racing exhaust package costs 507 Euros ($527 USD) and is available through the Athena official website.
The Athena racing exhaust system has a high-end aesthetic and is handcrafted with precision and attention to detail. The exhaust system, according to Athena, will provide unrivaled levels of performance, and is designed to ensure a precise gas expulsion flow, resulting in increased torque and acceleration. In addition, the exhaust kit is designed to maximize the performance of the Athena Big Bore cylinder kit for certain scooters.
Along with the big bore cylinder kit, air filters, Big Valve System, PWK carburetor, and racing crankshaft, the full racing exhaust was built and tested on the dyno. The small two-stroke motor produced a total of 19 horsepower in this configuration. It's vital to remember that the configuration is solely for usage on the track due to the increase in displacement and power. Most countries' traffic codes, as well as Euro 5 requirements, are incompatible with the exhaust kit and other performance-oriented enhancements.
Sources: Motociclismo, Athena Racing