O.S. Engine OSMG0930 FS-120S-E 4-Stroke Off-Ratio Powerplant  [OSMG0930]

O.S. Engine FS-120S-E
Price:
AUD$664.91
Brand:
O.S. Engine
Model:
OSMG0930
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

Reliable 4-Stroke Drive: O.S. Engine FS-120S-E

Hobbyists building serious models will find the FS-120S-E offers durable 4-stroke performance in a compact package. As part of the Surpass Series, it is engineered to cope with larger propellers while maintaining efficient running characteristics.

Camshaft Placement and Fuel Feed

The helix gear-driven camshaft is positioned at the front to improve mechanical stability and valve timing. Combined with the back-mounted updraft carburetor, the arrangement supports reliable fuel delivery and consistent combustion across flight regimes.

Prop Range and Setup Tips

The FS-120S-E supports a generous selection of propellers so modelers can prioritise climb, cruise, or scale realism. Recommended prop choices span from 13x11 up to 17x6 depending on aircraft weight and mission.

Specifications

  • Displacement: 1.218 cu in
  • Bore: 1.197 in
  • Stroke: 1.085 in
  • Practical RPM: 2,200-11,000
  • Output: 1.90 hp @ 11,000 rpm
  • Weight: 30.5 oz
  • Recommended Props: 13x11, 13x12, 14x10, 14x11, 15x8, 16x6, 16x7, 17x6

The FS-120S-E suits experienced builders after a stable, serviceable 4-stroke that can be tailored to different airframes and flying styles.

What mounting points should I check before flight?

Verify firewall alignment, secure engine bolts with proper lock methods, and ensure the prop hub and spinner clearance are correctly set to avoid vibration.

How do I choose a prop for aerobatic vs sport flying?

For aerobatics pick a smaller diameter with higher pitch to keep revs up, and for sport or scale climb use larger diameters to gain static thrust while keeping rpm within the engine's practical range.

Are there specific post-run care steps for 4-stroke engines?

After each flying session, cycle the engine with a few drops of after-run oil in the carburetor and turn the engine over to distribute preservative and prevent internal corrosion.

Can this engine handle larger scale model loads?

The FS-120S-E's torque and displacement make it suitable for many larger models, but confirm airframe weight and balance to ensure acceptable performance and handling.

Copyright © 2008-2026 rcjaz.com.au All rights reserved