OSM34721 O.S. ENGINES FSa-72II Airplane Engine w/F-5030 Silencer

Blow-by oil exits through the breather nipple on back plate for more
stable operation
Black rocker covers
61N aluminum body carburetor with rotary throttle lever, high speed
needle valve, and low speed mixture control, extended intake tube
eliminates reverse flow tendency of air/fuel mixture, carb is
reversible 180°
Adjustable F-5030 muffler for quiet operation can be rotated 360°
for tight fitting applications
Two-year limited warranty through Hobby Services beginning at date of
purchase

O.S. Engines FSA-72II Engine, F-5030 Silencer, Type F Glow Plug and
Manual

Fuel: 10%-20% nitromethane with 18% lubricant. Synthetic, castor, or
a synthetic/castor lubricant blend may be used.
NOTE: Certain four-cycle fuels cannot be used due to low oil content
However, SOME four-cycle fuels such as the Wildcat 4-Cycle 15%
may be used due to its 18% oil content.
When choosing fuels for this engine, be sure to select a fuel with
at least an 18% lubricant content.
Propeller: Sport & Aerobatic 12x7-8, 13x6-8
Scale 14x6-7

Displacement: 0.719 cu in (11.79cc)
Bore: 1.063" (20.7mm)
Stroke: 0.811" (20.6mm)
Max Power: 1.2PS/12,000 RPM, 1.18HP/12,000 RPM
Engine Weight: 16.79oz (476g)
Silencer Weight: 1.9oz (54g)
Practical RPM: 2,400 - 12,500
Crankshaft Thread Size: 1/4 x 28
Height from Bottom of Mounting Tab/Top of Rocker Cover: 3.5" (90mm)
Height bottom of Crankcase/top of Rocker Cover: 4.2" (108mm)
Width of Crankcase below Mounting Tabs: 1.4" (36mm)
Distance from Drive Washer to Rear of Carburetor: 4.1" (103.6mm)
Center of Mounting Holes Same Side: 0.79" (20mm)
Center of Mounting Holes Opposite Side: 1.8" (45mm)
Center of Front Mounting Hole to Drive Washer: 1.9" (49.5mm)
Center of Rear Mounting Hole to Drive Washer: 2.7" (69.5mm)
Center of Crankcase to Center of Needle Assembly: 1.3" (33.7mm)
Muffler Angle in Relation to Engine: 11°
Carburetor-
Needle Settings: High Speed: 2.5 - 3 turns out from fully closed
Mixture Control (low speed): 2 turns out from fully
closed