Dico wrote:

What do you run for sparkplugs in your TSIO550 engines -- the finewire or the regular ones?  Any comments or reviews?  Does one last longer than the other?  Which is better for LOP operatinos?

Dico,

I’ve run Champion massive electrode plugs in my TSIO 550 for about 750 hours, changing them at about 500 hours, “just because.” The electrodes were worn down, but still easy to gap and running fine. The “new” plugs have about 250 hours on them and look fine. I clean and re-gap them at 100 hours run time (every second oil change). They have performed flawlessly, less the one I dropped on the floor. This caused the inner white glass insulator to crack. Fortunately, it fell out so the defect was easy to see. I’ve never measured the internal resistance of these plugs (ref recent LML discussion), but thought I’d do this at the next cleaning to see how they measure up. I have always run this engine LOP.

I have never used fine-wire plugs in an airplane engine. They are a lot more expensive, and theoretically, have a much longer life. Against that, I’ve seen some with cracked center electrodes that required replacement with only a couple hundred hours of run time. Others could advise on these; my information is second hand.

Bob