Q&A for How to Gap a Spark Plug

Return to Full Article

Search
Add New Question
  • Question
    The gap for my car is .054. This is more than double the thickness of the thickest blade on a feeler gauge. Am I supposed to remove several blades from the feeler-gauge assembly and stack them?
    Community Answer
    Yes. Add more to get the right thickness, if your thickest leaf is too small. It's a very accurate way to measure or set a gap.
  • Question
    How would I know if my plug is pre-gapped?
    Community Answer
    It says on the inside flap of the box whether or not they're pre-gapped.
  • Question
    How do I find the gap on an NKG spark plug?
    Community Answer
    NGK offers an extensive pocket book, which is often given away for free at exhibitions and motor fair. You can usually find this sort of information on NKG's website as well. The correct gap depends on the motor type and may vary from the gap when buying it new.
  • Question
    What does 44,000 mean on the spark plug gap tool?
    Community Answer
    The distance of the gap between the center electrode and the side electrode is measured in thousandths of an inch.
  • Question
    What is the gap of the upper electrode?
    Community Answer
    It depends on the plug. Consult the owner's manual -- they will usually spec the plug and gap in the maintenance section. If you don't have the owner's manual, you may be able to download it for free -- manuals.lib has an extensive inventory.
  • Question
    How do I know the gap size for my vehicle?
    Community Answer
    Your owners manual should list the gap size in the back of the book; if you don’t have an owners manual, you may be able to download one online for free.
  • Question
    Is it necessary to change the spark plug wires when changing the spark plugs? Is it alright to re-use the same ones on new plugs?
    Community Answer
    It isn't necessary if the plug leads are in good working condition, but people often renew them when doing a plug change to be sure. you can ask a mechanic to check the resistance of your leads. It's an easy test, and shouldn't cost you.
  • Question
    How can I correctly remove the distributor from the engine?
    Community Answer
    Disconnect battery lead. Set the engine to top dead center by turning the crank shaft pulley clockwise. The crankshaft pulley has a mark or groove on the edge; line this up with the pointer or mark on the timing cover. When you remove your distributor cap, the rotor should be pointing where the lead to #1 cylinder would sit. If not, turn engine another revolution. When you have rotor pointing to right spot and engine set to TDC mark where the rotor points with a dot of paint. Undo distributor bolt and wiggle it up and out. Refit with rotor pointing to paint spot.
  • Question
    How do I adjust the spark plug gaps correctly?
    Community Answer
    It depends on the tool you are using. Auto stores will sell what looks like a half dollar coin with a hole at the top. That’s not to put on your key chain, it’s actually how you will gap your spark plugs. Put the ground strap in that hole and push down. If you are using the plastic round gap tool, then on the side where it’s shaped oddly, put one side of that in between the ground strap and electrode (making sure you do not brake the electrode). Push back until the desired gap is achieved.
  • Question
    How do I find the gap in a plug of a chainsaw?
    Community Answer
    If your finger can fit between the chainsaw and the base of the tree, then you need a new chainsaw.
  • Question
    What is the recommended gap for spark plugs for a 4E FE engine?
    Community Answer
    1 gap per plug is usually the safest though 2 or 3 gaps can be used in some situations, depending on the definition of gap at the time.
Ask a Question

      Return to Full Article