As noted on Yak 52 World, when conditions for condensation exists, moisture can collect in the high-tension lead's conduits and cause problems.  On my plane I have found that both the front and rear leads on cylinders #5 and #6 will collect moisture in the metal elbows due to their positioning. I have opened them up to find both water and oil present.

I have found running the engine closer to the upper green / lower yellow border of cht has helped.

If you are having consistent #2 mag drops, this is the first place to look.