Unleash upgraded power without sacrificing fit. The O.S. Max .55 AX delivers .50 scale muscle packed into a .40 size envelope. Its redesigned carburettor and muffler boost performance and ease, featuring a rear-angle needle valve for convenient tuning and a squared-off muffler for hassle-free cowling installation. Take your flights to the next level with the .55 AX - power, precision, and ease, all in one.

• Comes with the E3071 muffler for quieter efficiency

• Compact design means it has the same mounting dimensions as the O.S. Max .46 AX

• Power Box positionable muffler

• Angular head design offers increased surface area for better cooling

• 40K Carburettor with diagonally placed needle valve eliminates remote needle valve placement

• Advanced Bi-Metallic Liner process uses a double layer of plating material rather than one thick layer

• Plating process is more consistent, resulting in a more precise fit between piston and sleeve for better compression and longer life

• Recommended prop sizes: 12x7, 12x8, 13x6, 13x7

• Displacement: 8.93cc (.545cu/in)

• Bore: 23mm (.906in)

• Stroke: 21.5mm (.846in)

• Practical RPM: 2,000-17,000

• Power Output: 1.75 PS, 1.68 HP/16,000 RPM

• Weight w/o muffler: 405g (14.29oz)

• Weight w/ muffler: 525g (18.52oz)

• Aircraft blend fuel containing 5%-20% Nitromethane with at least 18% lubricant

• Plane

• Propeller