The 75AX is the next generation of "60 size" class airplane engines. It features the same bolt pattern as the original 61FX though boasts almost an a half a horsepower more! The 61A carburetor has an angled back needle valve which keeps your fingers much further away from a spinning propeller. Twin ball bearings support the hardened steel crankshaft for the ultimate in efficiency. Includes new 4040 Power Box™ muffler which increases volume for greater power, while at the same time being very compact. Angular head design looks great and significantly increases surface area for better cooling. This ABL (Advance Bimetallic Liner) sleeved engine will provide years of power and reliability. Fuel for this engine is recommended to use 5~20% nitro, with at least 18% oil content.
Features:
• Same bolt pattern as original O.S. 61FX, though almost half a horsepower more!
• Angular head design looks great while increasing surface area for better cooling
• Backward angled needle valve for easier and safer access
• Twin ball bearing supported hardend steel crankshaft
• Includes the new Power Box™ muffler, designed with more volume for increased power while still being very compact
• Advanced Bimetallic Liner (ABL) coating developed specifically by O.S.
Specs:
Displacement: 0.75 cu in (12.3cc)
Bore: 1.02 (25.8mm)
Stroke: 0.93 (23.5mm)
Practical RPM: 2,000-16,000 RPM
Power Output: 2.4 PS, 2.37HP15,000 RPM
Weight: 20.39 ounces (578g) wo muffler
26.46 ounces (750g) w muffler
Recommended Props: 14x6, 14x8, 15x7
Crankshaft thread size: 516-24
Distance from center of engine to drive hub: 2.62 (66.6mm)
Distance between exhaust bolt mounting holes 42mm
Height from crankcase bottom to top of cylinder head: 4.07 (103.5mm)
Heightcrankshaft center to top of cylinder head: 3.20 (81.5mm)
Width including mounting tabs: 2.4 (61mm)
Width not including mounting tabs: 1.67 (42.6mm)
Width between mounting holes same side: .98 (25mm)
Width between mounting holes opposite side: 2.04 (52mm)
Diameter of muffler body: 1.92 (48.8mm)
Angle of muffler in relation to engine: 4
Length from end of crankshaft to back of crankcase 5.09 (129.5mm)
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)
