An air-balanced engine assembly is configured to operate efficiently while producing a reduced level of harmful emissions. The engine assembly includes a two-stroke internal combustion engine with multiple power cylinders and intake and exhaust manifolds that fluidly communicate with the cylinders. The engine assembly also includes an air balancing assembly with valves that control intake air flow from the intake manifold to the cylinders. The valves cooperate to balance intake air flow among the cylinders and are configured to substantially equalize trapped equivalence ratios among the cylinders.