O.S. Max 75 AX ABL Aircraft engine with muffler has the same mounting dimensions as the O.S. Max .61FX. Advanced Bi-Metallic Liner process uses a double layer of plating material rather than one thick layer. This helps the metal bond to the cylinder and makes the plating more durable. Also, the plating process is more consistent, resulting in a more precise fit between piston and sleeve for better compression and longer life. Power Box muffler design provides more volume for increased power in a very compact shape. Angular head design offers increased surface area for better cooling Ball bearing-supported crankshaft. 61A carburetor with diagonally placed needle valve eliminating remote needle valve placement. Two year limited warranty.
Requires: Aircraft blend fuel containing 5%-20% Nitromethane with at least 18% lubricant.
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, 2.37HP/15,000 RPM
Weight: 20.39 onuces (578g) w/o muffler
Weight: 26.46 ounces (750g) w/ muffler
Recommended Props: 14x6, 14x8, 15x7
Crankshaft thread size: 5/16-24
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)
Height/crankshaft 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)