O.S. 61FX ABL w/Muffler

Tower Stock# LXBY46  •  Manufacturer Stock# 17750
Notes from our tech department:
This is one of the O.S. FX series of high-performance engines. This series
of engines is used in sport and aerobatic aircraft. The FXs are designed to
use a muffler or tuned pipe.

All FX engines are covered under the O.S. Max Two Year Warranty.


1-piece crankcase
Twin ball bearing-supported crankshaft
Schnuerle porting (AKA Schnuerle scavenging)
Advanced Bi-Metallic Liner. This process uses a double layer of
plating material, rather than one thicker layer. This helps the
metal to bond to the cylinder, and is more durable. Also, the
plating process is more consistent, resulting in a more precise
fit between piston and sleeve, for better compression, longer life.
Side exhaust with muffler with rotatable exhaust outlet
New carburetor with remote needle mounted on the backplate of the
engine (to keep fingers away from the spinning propeller).
Aluminum backplate.


One Expansion style muffler (E-4010) with screws
One Assembled engine with carb
One package illustrated instructions, parts list, and O.S. decal
One O.S. 8 glow plug (OSMG2691)


Displacement: 9.95cc (0.607 cu in) RPM range: 2,000 - 17,000
Bore: 24mm (.945) Stroke: 22mm (.866)
Horsepower: 1.90 BHP at 16,000 RPM Weight: 19.4oz, 23.6oz wmuffler
Length: 84mm (3.31) the distance from the backplate to drive washer
Width: 43mm (1.69) width of engine neglecting engine mounting flanges
52mm (2.05) distance between centers of the mounting holes
Height:100.5mm (3.956) Exhaust port: 29.5mm x 9mm rect
Crankshaft Thread Size: 516-24 43.8mm btwn exh mounting holes
Props: Tuned Pipe: 12x9, 12x10, 12x11
Sport: 12x6, 12x7, 12x8, 13x6, 13x7
Break-In: 11x7

High Speed Needle: 1.5 - 2 turns out from fully closed
Low Speed Needle: 2mm gap between the needle and spray bar at full
throttle (looking down the neck of the carb)


Fuel with 20 (minimum) lubricant content and 5-15 Nitromethane
(All 5-15 fuels we carry meet these requirements)

updt lmm 32709



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