This document is an instruction manual for O.S. engine, which introduces the components and operation of the engine
The O.S. FS-120S-E is an aircooled, overhead-valve four-stroke-cycle engine designed specifically for model aircraft use. It is produced by O.S., a company noted for pioneering quantity production of model four-stroke engines. The manual emphasizes that the engine is not a toy and requires careful handling due to its power and the risks associated with model engine fuel and rotating propellers.
The document covers the complete lifecycle of the engine, from initial installation and glow plug setup to starting, running-in, and maintenance. Key sections include detailed instructions for installing the carburetor, fuel tank, exhaust, and propeller, as well as procedures for adjusting the choke valve, throttle linkage, and idle mixture. Safety warnings regarding carbon monoxide, heat, and propeller safety are prominently featured throughout the text.
| Engine Type | Aircooled, overhead-valve four-stroke-cycle |
|---|---|
| Intended Use | Model aircraft |
| Suggested Fuel Tank Size | 400cc or 14 oz |
| Estimated Running Time | Approximately 10 minutes |
| Minimum Mounting Beam Size | 15mm or 5/8-in square section |
The engine must be operated in an open area and never in an enclosed space due to the risk of deadly carbon monoxide.
The engine requires very substantial mounting using rigid hardwood beams of at least 15mm square section, or a special O.S. cast aluminium radial motor mount.