Here is another Slick mag horror story.  About three months ago, I started getting an occasional miss in my engine (once or twice a flight.)  Over time, it got slightly more frequent but it was never more than one every few minutes.  With some experimentation, we discovered that pulling the LASAR circuit breaker solved the problem.  Also discovered that, while pulling the CB during ground run-up made a 300 rpm difference, doing so in flight made no difference to any engine parameter, regardless of the altitude at which it was done.  Hooking the controller box up to a laptop resulted in a perfect test score so the box and the mags went back to Unison (where nothing happened to them for 10 days but that's another story.)  Found out yesterday that the box tests perfect but BOTH mags are shot!  I have 320 hrs. tach time on them.

I learned the mag mantra early on (probably on my first preflight in 1967): mags are the world's most inefficient ignition system but we use them because they are SIMPLE, RELIABLE and SAFE.  And I believed it as a religious doctrine.  When I built my airplane, I selected the LASAR system precisely because it had not one but two of these safe, reliable things that would work no matter what if the new-fangled electronics failed.  Now I discover that for the last God knows how long, I have been flying around over mountain ranges and in hard IFR with TWO mags that went in the dumpster as soon as the Rockford people saw them.  As a final irony, they are pretty close to the only "Certified" parts on my engine (IO-540 exp).

I am getting a discount on two replacement mags which I intend to use while I figure out what electronic system to go to.  I intend to check them frequently, and I don't mean the run-up check that I have done before every take-off and that has always been perfect.  Check out whatever Deakin article claims that runup checks are a complete waste of time, which I now put more stock in than I used to.  I have no idea if the controller box is contributing anything but I intend to test that too when I get it reinstalled.  And I still don't know why the engine missed only with the LASAR system on.  Without it, I would presumably still be fat, dumb and happy (instead of being only two of the foregoing) flying around with two "shot" mags tbat do just fine on runup.