The O.S. Max 75AX is a high-performance, two-stroke nitro glow airplane engine manufactured by O.S. Engines. It is specifically engineered to deliver .75-size power while fitting seamlessly into the compact mounting footprint and bolt patterns of a standard .61 FX size engine class. This drop-in sizing makes it a popular upgrade choice for radio-controlled sport and scale model aircraft.
Displacement: 12.29 cc (0.75 cu. in.)
Piston Stroke: 23.5 mm (0.93 in.)
Weight: 578 g (20.39 oz) without muffler / 750 g (26.46 oz) with muffler
Carburetor: High-precision Type 61A Carburetor
Included Silencer: E-4040 Power Box Muffler
Advanced Bi-Metallic Liner (ABL): Uses an un-ringed piston technology with a specialized multi-layer cylinder plating process. This provides a highly consistent fit, long-lasting durability, and optimal compression.
Power Box Muffler Design: Features a unique, compact expansion chamber design. It creates a larger internal volume to increase engine output while maintaining compact lines and superior noise suppression.
Diagonally Angled Needle Valve: Eliminates the need for a separate, remote high-speed needle valve installation. The rearward angular placement helps keep fingers safely clear of the spinning propeller during adjustments.
Angular Cooling Head: Features a square, aggressive heat-sink fin layout. This design provides enhanced total surface area to keep the engine operating cool under sustained heavy loads.
