The FS-200 is a new model which is the largest four stroke engine in the FS series. This big single which has larger cylinder bore and longer stroke than any of those , is a proposal from OS to experience the feeling of flight with four stroke engine in a large airplane. As a matter of course, the easy-to-handle power characteristic that is a well-known feature of the FS series have been retained in this big engine. The new silencer of distinctive design is equipped as a standard accessory. The FS-200S is also a model with which you can expect the future of O.S. four cycle engines.