In order to measure research engagement of academicians, will it be wise to use the JES (Job engagement scale) by Rich et al. (2010) with modifications in words like (Research activities instead of Job)?
It depends on the operationalization of the construct of enjoyment. Currently, the most popular enjoyment scale is Utrecht Work Engagement Scale (UWES). You may check out the comparison of JES and UWES by Byrne et al., (2016).
Reference
Byrne, Z. S., Peters, J. M., & Weston, J. W. (2016). The struggle with employee engagement: Measures and construct clarification using five samples. Journal of Applied Psychology, 101(9), 1201–1227. https://doi.org/10.1037/apl0000124
Article The Struggle With Employee Engagement: Measures and Construc...
First, you have to consider your conceptual framework and operationalisation. Changing a few words in the Job Engagement Scale (JES) to get the measures of research engagement of academics is a simple way. Your intention would be okay. But, it is important to pay attention to put appropriate words that should validate your research problem identification and objectives.