Mark and I made a quick run to the airport this morning to remove the bottom plug on the number four cylinder. With the help of a 1/2" swivel and a shorter extension we didn't have to remove the bottom cowl. As you can see from the picture there was a big carbon lead snot that attached itself to the fine wire plug electrode. If you look closely you can also see a few of the snotball's friends. With the help of the new picks the plug was cleaned, the gap checked, and I gave it a once over with a bronze bristle brush. Everything looked good to go so we added some anti-seize and reinstalled.
Since it was Thanksgiving we left the cowl on the moving blankets so we can test run tomorrow, then cowl and get back in the air.
Thanks to Mark G for all his help!
8 comments:
I can only run fine wires on the top plugs; if I use them on the bottom plugs they quickly foul just like you show here. So I’m running massives on the bottom and fine wire on the top.
My Lycoming is the opposite.
Gary,
Running fine wires on the bottom should result in fewer fouled plug issues on runups. Are you leaning to peak for cruise? EGTs shouldn’t exceed 1450 on any cylinder and I very rarely ever had to clean the fine wires with a 50 hour inspection/cleaning/rotation regime while always leaning to peak in cruise. As you are now well aware, 3TC never has CHT issues running EGTs at peak in cruise. Helps keep the plugs clean. Lyc also approves and recommends the practice.
Bill
Goes without saying that always leaning VERY aggressively for taxi is a best practice. Lean such that advancing the throttle beyond 2000 RPM will cause the engine to falter. I lean to the point that I need to enrich my lean just to do a run up.
Bill, 3TC always runs around 1430-50 across all cylinders and CHT’s 320ish in cruise.
I have also started following lycoming’s reccomendation at shut down.
Gary, the snot ball is lead, not carbon. You are running rich. Red knob full rich only at startup and climb out. Otherwise peak.
You are absolutely correct. My brain fart!
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