We report on precision mass measurements of 113,115,117Ru performed with the JYFLTRAP double Penning trap mass spectrometer at the Accelerator Laboratory of University of Jyväskylä. The phase-imaging ion-cyclotron-resonance technique was used to resolve the ground and isomeric states in 113,115Ru and enabled for the first time a measurement of the isomer excitation energies, Ex(113Rum)=100.5(8) keV and Ex(115Rum)=129(5) keV. The ground state of 117Ru was measured using the time-of-flight ion-cyclotron-resonance technique. The new mass-excess value for 117Ru is around 36 keV lower and seven times more precise than the previous literature value. With the more precise ground-state mass values, the evolution of the two-neutron separation energies is further constrained and a similar trend as predicted by the BSkG1 model is obtained up to the neutron number N=71.