I rally myself to get curious about the data, and to know/hope that the more 'tedious' steps are building an interesting picture for analysis. In other words, I have the 'end goal' in sight (ie: career aspirations, completing program requirements, satisfying intellectual curiosity, etc).
When the interest in the data collection, etc, is losing all meaning, I encourage students to:
1) re-orient towards the initial curiosity in the hypothesis (big picture)
2) 'accept' the tedium, and develop a mantra about meeting a goal (ie: career goals, publication, etc)
3) take some intentional days off (gasp), and make a plan for when you will re-engage
4) if you are learning that you do not love every aspect of research, this is good learning
5) the typical behavioral suggestions -- build in rewards for your efforts, and be specific, follow through