O.S. Engine OSMG0981 81FS-a High Torque 4-Stroke for 60-Size Models  [OSMG0981]

Unlock Smooth 4-Stroke Performance with the O.S. Engine 81FS-a

The O.S. Engine 81FS-a, model number OSMG0981, suits hobbyists seeking a robust 4-stroke upgrade for 60-size models. It occupies the same space as the FS-70SII, allowing straightforward swap-ins while offering improved midrange and top-end response.

Design choices that cut maintenance

This engine features a closed lubrication system that removes the need for crankcase ventilation, which reduces oil loss and routine fiddly adjustments. The 60RA carburetor fitted with a venturi helps manage air-fuel flow and reduces the risk of fuel reaching the cowl. A rubber O-ring on the muffler manifold further helps prevent oil leaks at the exhaust interface.

What to expect from the spec sheet

The O.S. Engine 81FS-a combines sensible engineering and dependable output, making it a smart 4-stroke choice for sport and precision flying in 60-size airframes.