With a displacement of 121.6 cc, the FG-120TS is currently the strongest engine in the Saito program and is ideal for aerobatic models in the 70 cc class, as well as scale and semi-scale models in the 70-100 cc range. Two-blade propellers in the range of 27x12" to 28x12" can be used. The RPM range is between 1000 and 6000 RPM. With a Falcon 27x12" propeller, the engine reaches a maximum speed of 5000 RPM. The fuel mixture should initially be 15:1 and can be changed to 20:1 after the break-in period. Saito recommends using "Deluxe Materials Power Model 2T-S" motor oil. For ignition operation, a battery larger than 1500 mAh is required, with a voltage range of 6-12 V, meaning 2-3S LiPo or LiFe.

The stunning 4-stroke engines from Saito have been known for their highest quality and reliability for years. Saito engines originate from the era of glow plug engines and are always designed as 4-stroke, available in a black casing with a golden valve cover or in a silver casing. Later, modern large-displacement gasoline engines followed in various cylinder configurations, also in the typical 4-stroke design. These gasoline engines quickly gained popularity as they were considered powerful and reliable from the start. Gasoline engines have a lower fuel consumption than glow plug engines, and the fuel is significantly simpler. The electronic ignition allows for starting the engines without a glow device, greatly improving user comfort compared to earlier engines. Typically, regular unleaded gasoline is used in conjunction with high-quality 2T oil in a ratio of 15-20:1. An English-language manual is included with the engine.