Just read the maintenance logs for a 1982 Cessna 172 we have in the hangar

I was doing some paperwork and pulled the logs for this old bird. Found out it's still on its original factory spark plugs from over 40 years ago. The book shows they were installed in 1982 and have never been changed, just cleaned and gapped. The plane only flies about 25 hours a year, but that's still over a thousand hours on the same plugs. I always heard those old Champions were tough, but this seems crazy. Has anyone else seen a set of plugs last that long in a light aircraft?

3 comments

3 Comments

mark_hernandez121mo ago

Original factory spark plugs" just shows how things were built to last back then.

gibson.sean1mo ago

Lol come on, they were just cheap copper plugs. They lasted because the engines ran like garbage and barely made any power. My old truck's "original" ones were fouled out and misfiring at 60k miles.

kim.emma6d ago

My buddy had an old F-150 from the early 90s that still had the original plugs when he bought it at 100k miles. He pulled one out just to check and half the electrode was basically gone, but the thing still started every morning without fail. The real trick back then was that those engines had such low compression and primitive timing that fouling was almost impossible. They didn't really "last" in any impressive way, they just kind of limped along until you finally bothered to change them. Definitely not the same as something built for actual longevity now.