The new FSa-81 is a direct replacement for the FS-70 Surpass II, offering greater power and throttle precision in a compact and lightweight design. The crankcase mounting dimensions allow the FSa-81 to slot into the same mount that an FS -70S II would for an instant power upgrade.

Like the FSa-56, the crankcase breather system has now been incorporated inside the engine to negate the need for an external vent and the excess oil that eminates from it. A propeller locknut assembly is of course standard.

The new F-5030 silencer is very effective, thanks to it's internal baffle and carefully matched internal volumes and opassages. The design allows a huge range of outlet positions to accomodate almost every model. Even the distance away from the engine can now be adjusted.

The latest 60RA carburettor now features a 'constant velocity' inlet for improved throttle response and reduced spitting.