The last time I flew, I noticed that my #2 cylinder EGTs were intermittently going low. CHT has always been cooler on this one than the rest and that didn't really change. I also noticed it was hard to start..... It wouldn't fire until I released the key. But as soon as I released the key it fired instantly with the prop still spinning. Yesterday we went up for a bit and I noticed the same thing on start up....no fire until releasing the key. Mag drop increased a little bit and is now 100rpm vs. 75 on the right mag. I flew it for a bit and that #2 cylinder got cool enough in the climb that I got a caution light from my UBG16. I returned to the airport. Guessing impulse coupler has failed? I've got another servicable mag on the shelf that I can swap in. May go ahead and order that Surefly. Regardless, im going to have my IA come down and look at it with me.