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