Great Reason to Buy Tools
I used ATS (
Aircraft Tool Supply) to show you tools to do a spark plug cleaning.
You will need a 7/8" or 3/4" deep socket. There are special sockets for aircraft spark plugs, but you can get a way with deep sockets some times.
You need a way to organize the plugs like a
TRAY. You can make one of wood or metal to hold the plugs with the cylinder number and TOP or BOTTOM position.
When you clean plugs you usually rotate tops and bottoms and move to the next cylinder and need to keep track of them.
For a 4 banger switch these pairs:
1T to 4B
2B to 3T
1B to 4T
2T to 3B
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Vibrating tool for getting the lead deposits out of the deep pockets on side of center electrode. The cost is not too much. The Pro ones are expensive, but $25 gets you a cheap one. You could probably pick it out manually.
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Gap tool Cheap and
Expensive (You can get cheap ones on up to very expensive. It precisely bends the massive electrode without damage to the center conductor or porcelain.)
Bead blast (Harbor freight has them on sale for next to nothing sometimes.) -AND- You will need
blast medium
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Gap measuring tool -OR-
(cheaper) Gap measuring tool
Spark Plug Thread Lubricant (This is a must, BUT only put a drop in the top two threads. Use sparingly. You don't want any of it to get on the end of the plug or in the cylinder. Keeps plug from seizing in hole.)
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Extra washers (Washers get worked hardened over time or damaged. You can re-soften (anneal) old washers and re-use by heating them with a propane torch. String one from a safety wire and hold over the torch until the color changes, barely glows dull in a darkened room, than quenched in water. The quench is not really necessary or critical, just convenient. You will need a little gas torch. Acetylene is a good way to melt them. Soft and melt is not far apart. Propane is safer.)
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Spark Plug "Pressure Tester" It puts the plug under pressure and checks it can spark. Its not something you are going to buy ($500-$1400) but most FBO's have them. Try and do a test before reinstalling.
Reinstall but
DO NOT OVER TORQUE! You should use a sensitive INCH-POUND torque wrench, preferably one that is calibrated. I use a plan old beam type for the plugs. Lycoming calls for spark plugs to be torqued: 30 Ft. LB (360 in. Lb) to 35 Ft. Lb (420 In. Lb). I have no reason, but I tend to under torque just below the 300 in-lbs. Never had a plug get loose.
Clean the spark plug lead and contact before reinstalling. The lead nut (3/4" or 5/8") does not need to be too tight. There is a spec torque but its too hard to read on a nut you can't get a socket on, so I just make it snug. Just don't over do it. It's very rare people under torque, unless they just forget to tighten it all together.
If you DROP a spark plug once DROP it twice, in the trash. A hairline crack can damage an engine and cause pre-ignition. So if it hits to floor throw it away.
Cleaning plugs is fun and its a great excuse to buy a bunch of tools.
PS: DON'T USE GAS FOR CLEANING IF AT ALL POSSIBLE! Its a great way to catch on fire or blow your hanger up. Use part cleaning solvent or mineral spirits. We all have done the gas thing, but it's not really safe. It's very flammable.
