FS-70 Ultimate

Pumped-up 4-stroke engine technology.

It's the new pinnacle of performance for today's aerobats! The FS-70 Ultimate 4-stroke powerhouse promises smoother, more consistent muscle, thanks to an ingenious pump system that offers consistent fuel delivery, regardless of the plane's attitude. And amazingly, this “pumped-up” power comes from an engine that weighs less than the FS-70 II engine without a pump

The FS-70 Ultimate (shown here on the right) is noticeably more compact than the O.S. FS-70 II, making for easier installation in a wider range of aircraft.

The most important new innovation found on the FS-70 Ultimate is a Pump System incorporated on the back plate. It pressurizes the fuel tank for constant fuel delivery at any attitude.

This is the 4-stroke engine that enjoys the more linear response of a slide-valve carb, for quick and accurate throttle response. It also features a regulator that stabilizes the pressurized fuel for reliability during maneuvers.

One way O.S. has efficiently removed overall weight from the FS-70 Ultimate is by drilling holes in the drive washer.