My mistake with a Cessna 172 spark plug at KSMO cost me a whole afternoon last month

I was working on a Cessna 172 at Santa Monica airport last month, and I swapped a spark plug without checking the gap first. The engine ran rough on the test run, so I had to pull the plug back out and regap it. Took me an extra 45 minutes to get everything back together and run the engine again. My coworker said I should have used a feeler gauge from the start, and he was right. Now, before I touch any spark plug, I always check the spec sheet and the gap. Has anyone else here made a similar simple mistake that snowballed on them?

2 comments

2 Comments

rubybarnes15d ago

Who lets you near a plane without a feeler gauge?

hugo_moore15d ago

Learned that lesson the hard way too, always gap before install.