Abstract
Effect of the carbon canister on motorcycle emissions and the way to diminish this negative effect has been investigated in this paper. Abundant experiments are carried out on a 125ml 4-stroke motorcycle to research the saturation absorbed fuel amount in carbon canister when motorcycles in a long idle time state and the diurnal fuel evaporating character when motorcycles in daily application state. Then the effects of the purge fuel on the dynamic air fuel ratio, the emissions concentration and the final total emission are studied during UDC containing 6 urban test cycles. Based on these results, an electronic valve is settled between the carbon canister and the intake pipe to control the purge timing to achieve a lower emission of the motorcycle emissions.