In this study we present the results of synthesis and characterization of single crystals of the antiferromagnetic intermetallic compound YMn2, unalloyed and with chemical substitutions, using a Sn-flux technique. In particular, we inspect the effects of Cu chemical substitutions in the Mn site of YMn2, and investigate the Cu-concentration dependence of the magnetic properties of this compound. Comparing our results to previous ones, we discuss the interplay between its doping induced properties