3x7mm Push Rod O-rings, intended for use with the O.S. 91HZ F3C, and 91HZ-PS 3D Helicopter Engines, as well as the O.S. FS-110-a, FS-120S-E, FS-120 III, FS-200S-P and FS-200S four stroke airplane ...
4-Stroke Pumped Engine. 200-size power in a 120-size package! How do you get 200-size power from a 120-size engine? O.S. calls it the FS155-a. Since the FS155-a is a pumped 4-stroke, you’ll ...