Engine for transport vehicle

摘要

A number of embodiments of vehicles such as scooters that are powered a compact, high performance, four-cycle crankcase compression supercharged internal combustion engine. The engine is provided with two throttle valves, one on the intake side and one on the compressor side, that are operated simultaneously and in the same direction under at least some conditions so as to improve throttle response. In addition, an arrangement is provided for limiting the maximum pressure in the compressor side under low throttle and low load conditions. This improves performance and ensures against seal degradation in the lubricating system.