O.S. Engine OSMG0650 120AX Lightweight 3D Airplane Engine  [OSMG0650]

O.S. Engine 120AX
Price:
CAD$400.03
Brand:
O.S. Engine
Model:
OSMG0650
Please kindly input your name and email address, we will inform you once we have the restocking.
Or you may find similar product under the
category
Write a review

Push Your 3D and Sport Flying Further

For pilots who want to expand 3D, precision, and sport routines, the O.S. Engine 120AX fits into the same footprint as a .91 engine while delivering roughly 20% more displacement. That extra capacity helps spin larger props more efficiently without compromising handling.

Built for Balanced Power and Control

Weighing just 21 ounces (650 grams), this engine adds minimal mass compared with a .91, so aircraft balance and agility stay intact. The angular head increases surface area to improve heat transfer and promote consistent running and longer component life.

Practical Features and Fitment

Featuring CCD mounting compatibility, the 120AX installs where a .91 once sat and includes a #8 glow plug, a 70D dual-needle carburetor, and the E-5020 Power Box muffler with two adapters. Typical propeller choices are the 14x10 APC and 15x6 APC to suit different flying styles.

Specifications

  • Displacement: 1.20 cu in (20 cc)
  • Bore: 1.197 in (30.4 mm)
  • Stroke: 1.083 in (27.5 mm)
  • Practical RPM: 1,800-9,500
  • Output: 3.1 hp @ 9,000 rpm
  • Weight: 21 oz (650 g)

The O.S. Engine 120AX is a solid upgrade for intermediate and advanced hobbyists seeking more thrust without sacrificing handling, providing a reliable mix of power, cooling efficiency, and easy installation.

Will this engine mount in my plane that uses a .91 block?

Yes. The 120AX is made to sit in the same mounting area as standard .91 engines, so most mounts and firewall layouts will accept it with minimal modification.

Which prop gives the best all round performance?

For a balance between vertical power and economy, pilots often choose the 14x10 APC; the 15x6 APC is better for faster sport flying where a smaller diameter is preferred.

What maintenance keeps the 120AX running well?

Regularly check glow plug condition, clean the carb needles and muffler, and verify head bolts are secure. Keep cooling passages clear to maintain reliable temperatures.

Can beginners use this engine safely?

It is usable by motivated beginners, but because of its higher output it is recommended for pilots who have some experience or who fly with an instructor present when first learning the setup.

Copyright © 2008-2026 rcjaz.ca All rights reserved