O.S. Engine OSMG0990 110FS-a Four-Stroke Compact Powerplant  [OSMG0990]

Compact power from the O.S. Engine OSMG0990 110FS-a

RC airplane pilots seeking more punch without extra bulk will appreciate the O.S. Engine 110FS-a Four-Stroke. With 12.5% more power than the FS-91SII while keeping a similar footprint, this engine is a practical upgrade for models where space and weight are critical.

Recycled blow-by lubrication for cleaner operation

The O.S. Engine 110FS-a uses a blow-by recycling system to feed lubricating oil back into the engine internals, cutting friction and extending service intervals. That approach reduces external oil buildup and simplifies post-flight cleanup, so you can spend more time flying and less time maintaining.

360-degree muffler positioning for easy installation

Its F-5040 muffler rotates fully for flexible placement on your airframe, helping you achieve an ideal fit and a deep, satisfying exhaust note. The engine retains the FS-91SII mounting bolt pattern, making it straightforward to swap into existing mounts.

Simplified setup and durable design

Features like a reversible carburetor and a slimmer camshaft housing make installation easier and packaging neater. Tighter manufacturing tolerances and the updated internal design lower routine maintenance demands, so sport and scale pilots get reliable, long-lasting performance.

The O.S. Engine 110FS-a Four-Stroke is aimed at hobbyists who want higher performance with minimal fuss; its efficient lubrication and adaptable muffler make it a strong choice for a wide range of RC aircraft.