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Instruction Manuals:	Manual 1 (1.4 MB)
Tower Catalog Page:	196

 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. This Ringed engine has a steel liner.

FEATURES: One-piece crankcase
          Twin ball bearing-supported crankshaft
          Schnuerle porting (AKA Schnuerle scavenging)
          Aluminum piston, steel cylinder liner and iron piston ring
          Side exhaust with muffler with rotatable exhaust outlet
          Carburetor with remote needle mounted on the engine back plate
            (to keep fingers away from the spinning propeller).
          Two-year warranty

INCLUDES: 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)

SPECS:    Displacement:      14.95cc (0.912 cu in)
          RPM range:         2,000 - 16,000
          Bore:              27.7mm (1.090")
          Stroke:            24.8mm (0.976")
          Compression Ratio: 10.1 : 1
          Weight: 550g (19.42oz)   24.3oz w/muffler
          Horsepower:        2.8 BHP at 15,000 RPM
          Length: 96mm the distance from the backplate to drive washer
          Width: 42.6mm width of engine neglecting engine mounting flanges
                   52mm distance between centers of the mounting holes
          Height: 103mm
          Crankshaft Thread Size: 5/16-24
          Props: Hobby Services recommends a 13x8 or 13x9 prop (6/99)
          NOTE: Exh port same size as .61SF so can use 61SF Header w/91 Pipe

         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)

REQUIRES: Fuel: 18% (minimum) conventional lubricant content and 5%-20% Nitro.

COMMENTS: All FX series engines are covered by the O.S. two year warranty
          Engine mounting & exhaust dimensions are the same as .61FX.
          Engine guru Clarence Lee tached this engine w/various props
           Prop Size              RPM
              13x6              12,500
              13x8              10,400               using a 13x8 prop,
              13x10              9,500               Hobby Services tached this
              14x6              10,900               engine at 11,300 RPM
              14x8               9,500                                  6-24-99
              14x10              8,400
              15x6              10,200
              15x8               8,100
              16x6               8,300

MORE COMMENTS: O.S. now uses an updated Back Plate (Cover Plate) and Needle
                Valve setup for this engine. It now uses the following:
                - OSMG4078   29057000 COVER PLATE 91SX-H
                - OSMG6997   26582900 VALVE ASSY 40-65LA
                - OSMG7152   26582931 NEEDLE STAY 91FX
                                                                WLG 10-16-98
                                                                       ir/jl
                                                           updated 05/10/04 tjt
                                                              updt jxs 10/17/05
                                                               updt lmm 3/27/09



– If you need more information, use these O.S. resources –

Click Here: Manufacturer's Product Web Page
E-mail: enginesupport@hobbico.com
Web Site: http://www.osengines.com/
Phone: 217-398-8970


 
Postal Address:
O.S.
3002 N. APOLLO DRIVE, SUITE #1
CHAMPAIGN, IL 61822  








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