Orion BN/KL presents a highly isotropic molecular outflow which belongs to a rarely found kind of objects associated with stellar formation. It contains about 200 H2 filamentary structures known as fingers possibly generated in an common event between 500 and 1000 years ago. This outflow has been deeply studied in recent years. Zapata et al. (2009) noted the explosive properties of the region analyzing the CO J=2-1 transition and found that 500 years is more likely to be the real age of the event. The discrepancy in the age of each finger could be produced by the assumption of ballistic motion. So, the inclusion of dynamical friction could improve the age determination of the explosive event. There are just a few events as Orion BN/KL, suggesting a very short lifetime for this objects. This could be explained if the clumps are losing mass. In that scenario, the finger's motions equations would be affected. In this work we describe the motion of both a plasmon and a clump using different mass loss rates and compare the results with hydrodynamical 2D numerical simulations. We apply this results comparing with observations of radial velocities and proper motions. Finally, we conclude with some constrains in the ejection mechanism and the possible age of the event.