You don't compromise, and you don't want your engine to, either. The FS110-a doesn't compromise on performance, delivering 12.5% more power than the FS-91SII in the same space! But high-performance doesn't mean high-maintenance. Engine blow-by is trapped and re-used to constantly lubricate and bathe the engines working parts inside reducing friction and prolonging engine life. Plus, the new system eliminates messy cowls and other oil drainage. What's left is a first-rate engine that sets new standards and exceeds all expectations. It's the FS110-a from O.S. - the 4-stroke with muscle.