Tecno Streetline exhaust for 4-stroke scooters. The Portuguese manufacturer Tecno has adapted the internals to meet the needs of a small 4-stroke engine. As the 139QMB/A or GY6 50 have a relatively high valve overlap, the correct dynamic pressure is precisely the secret for optimum engine performance. Acceleration improves significantly and this helps increase power to a higher top speed. Currently one of the strongest assets of our product range. The sporty looks Suitable for very with the rear body shape. The exhaust is not restricted, and so does not have an E-certification.