The STIHL 4-MIX engine is the first four stroke engine which works on a mixture of petrol and oil. It combines the advantages of four-stroke and two-stroke engines in one. With higher torque and up to 80% less emissions and a deeper more pleasant sound. Combined with a well balanced, bike handle, as a light brushcutter, it makes the FS100 a leader in its class. Fitted standard with AutoCut + metal blade cutting heads.
| Displacement | 31.4 cm3 |
| Power output | 1.0/1.4 kW/PS |
| Weight Without cutting tool and deflector | 5.6 kg |
| Fuel capacity | 0.53 l |
| Overall length | 1.80 m |
| Cutting blade | Metal blade + AutoCut |