Development of a Catalytic Exhaust System for a Two-Stroke Scooter Engine

An experimental investigation was carried out to highlight the impact of different catalytic exhaust systems of a typical European two-stroke engine for small scooters on exhaust emissions and on engine performances. In particular different chemical compositions of the active coating materials and different precious metal loads were tested, and several geometries of the monolith in the exhaust system were analyzed. The influence of different carburetor settings on the efficiency of the catalyst and on engine performance was also evaluated. Finally, durability tests were performed, by monitoring the efficiency of the catalyst during a 12000 km aging test.