Same mounting dimensions as the O.S. Max FS-70 Surpass
Ideal fit for 60 size planes
Specially designed lubrication system eliminates need for crankcase
F5030 muffler with rubber O-ring in multi position manifold to help
prevent oil leakage
O.S. FS81-a 4-Stroke Aircraft Engine, carburetor, muffler, header,
type F glow plug, 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%
(CATP9109) 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 and aerobatic scale 13x7-9 or 14x6-7
Displacement: 0.809 cu in (13.26cc)
Bore: 1.091" (27.7mm)
Stroke: .866" (22mm)
Weight with Muffler: 20.11oz (570g)
Practical RPM Range: 2200-10,000
Output: 1.3 PS, 1.28 HP @ 11,000 RPM
Height from Bottom of Mounting Tab/Top of Rocker Cover: 3.8" (97mm)
Width of Crankcase below Mounting Tabs: 1.6" (40mm)
Center of Mounting Holes Same Side: .83" (21mm)
Center of Mounting Holes Opposite Side: 2" (50.8mm)
Center of Front Mounting Hole to Prop Washer: 2.2" (55.5mm)
Center of Rear Mounting Hole to Prop Washer: 3" (76.2mm)
Center of Crankshaft to Center of Needle Assembly: 1.4" (36mm)
Center of Crankshaft to Outer Edge of Carburetor: 1.8" (45mm)
Muffler Angle in Relation to Engine: 10°
Needle Settings: High Speed: 2.5 - 3 turns out from fully closed
Mixture Control (low speed): Flush with carb body,
then 1 turn in.
updt lmm 4/6/09