Specifications:
Displacement 4.07cc (0.248cu.in)
Output 0.8ps/0.79hp/16,000r.p.m.
Bore 18.0mm (0.709in.)
Practical r.p.m.Range 2,500-17,000r.p.m.
Stroke 16.0mm (0.630in.)
Weight 275g (9.70oz.)

Prop rpm data by suggested propellers (For reference purpose only):
9x5 15,100
9x6 13,500
9.5x5 13,300
10x5 11,650

O.S. has now introduced an engine that not only has great performance but “easy-to-handle” characteristics as well allowing the average modeler to enjoy a more casual and relaxed type of flying. Considerable development has resulted in the new generation “AX Series” 2-stroke engines which feature “easy-to-handle” characteristics as well as a more pleasant exhaust note and the ability to turn one size larger propeller at lower rpm. The latest addition to the AX line is the MAX-25AX - the smallest brother in the series. The 25AX can replace current 25 size engines due to having the same mounting bolt pattern. Due to the engine’s wider power band it can be used to power a variety of small airplanes such as trainers, sport models, etc.

The MAX-25AX maintains the same overall form as well as fin shape and slant head that symbolize the AX Series.

A newly designed “POWER BOX” silencer is supplied with the engine that offers not only quieter and milder exhaust sound but excellent power as well. Also, the exhaust outlet direction can be rotated to meet specific applications.