By increasing the stroke, not only propellers of 12x7-8 and 13x6 sizes, but also propellers with large loads (13x7-8, 14x6) can be used without any loss of power.

 A newly designed cylinder head is adopted along with the increased displacement. The internal capacity of the combustion chamber has been expanded to achieve more realistic 4-stroke exhaust sound and more power.  

The F-4051 silencer, which is a unique design of the FS-V series, has revised the internal dimensions and improved the exhaust efficiency while maintaining the comfortable 4-stroke sound. 

The drive washer has been changed to a machined aluminum with a woodruff key. Additional standard equipment is set if lock nuts that prevents the propeller from coming off.