This paper presents an experimental work on the determination of viscoelastic solution properties from the analysis of their behavior when subject to the capillary instability. Known as the jet rheometer method, such an approach is reserved for low-viscous viscoelastic solutions for which commercial techniques are unsuitable. In the present work, the injection conditions are free and cover a wide range of operating points. The analysis is statistical in nature and uses a multi-scale description tool that allows access to all dynamics involved and, in particular, to those of small characteristic scales. The results are numerous and evidence the presence of polymer mechanical degradation due to the injection. The influence of the operating conditions on this mechanism is highlighted.