Today I thought of that as I did my magneto check. Left was fine, right dropped a bunch and was rough running. A few common solutions came to mind but at the end of it the right mag just wasn't cutting it. I taxied back, shut her down and pondered. Got out and decided to pull the upper cowling off only to find a loose plug wire. Yes, I had done a preflight and I always 'push' on the plug wires as a routine check. Son of a gun. No explanation.
Started right up (no choke) taxied back out and this time the run up was fine. I took off with the intent of staying close 'just in case' but all indications were good. Sally and I did a small round robin underneath the shelve of the Philadelphia Class B airspace with a stop at Cross Keys. Along the way we flew over KLOM, 19N, 7N7 and KPTW.
The procedures work if we take the time to use them.