O.S. FSa-56 II with F-4040 Silencer (2729N)

Latest version of this popular sized, high-performance four-stroke engine.

Features a black rocker cover to suit the appearance in scale models better plus a revised oil breather system. The breather now vents from the crankcase rather than being re-ingested in the inlet, to improve running consistency.


The popular FS56-a now features upgrades that make it even better than before!
Blow-by oil exits through the breather nipple on the back plate, for more stable operation.

Black rocker covers gives this engine a more impressive appearance.
The F-4040 silencer can be positioned to achieve the ideal fit.
Mounts with no-mod ease in the same space as the FS-56a.

Recommended Fuel: 10%-20% nitromethane with 18% lubricant. Synthetic, castor, or<br />a synthetic/castor lubricant blend may be used.<br />When choosing fuels for this engine, be sure to select a fuel with<br />at least an 18% lubricant content.<br />Propeller: Sport & Aerobatic, 13x6, 12x6, 12x7, 12x8<br />Scale, 13x6, 13x7, 12x6, 12x7, 12x8<br /><br />Displacement: 0.569 cu in (9.32cc)<br />Bore: 0.945" (24mm)<br />Stroke: 0.811" (20.6mm)<br />Engine Weight: 13.9oz (394g)<br />Output: 1.0 ps/0.99 hp @ 10,000 rpm<br />Practical RPM: 2,400 - 13,000<br />Crankshaft Thread Size: UNF1/4 x 28<br />Height from Bottom of Mounting Tab to Top of Crankcase: 3.3" (84mm)<br />Width of Crankcase below Mounting Tabs: 1.3" (34.1mm)<br />Center of Mounting Holes Same Side: 0.69" (17.5mm)<br />Center of Mounting Holes Opposite Side: 1.7" (44mm)<br />Center of Front Mounting Hole to Drive Washer: 1.98" (50.3mm)<br />Center of Rear Mounting Hole to Drive Washer: 2.6" (67.5mm)<br />Center of Crankcase to Center of Needle Assembly: 1.3" (32.5mm)<br />Center of Crankcase to Outer End of Crankshaft: 3.5" (88mm)<br />Muffler Angle in Relation to Engine: 11°<br />Mounting Hole Diameter: 0.14" (3.7mm)<br />Carburetor;<br />Needle Settings: High Speed: 2.5 - 3 turns out from fully closed<br />Low Speed: Flush with carb body