Autelite:XST2974DP / 2974
1) 1pc in a small box, 10pcs in a middle box, 200pcs in an export
2) 4pcs in a blister packing, 200pcs in an export carton;
3) 100pcs in a polyfoam box, 200pcs in an export carton;
4) 9600pcs spark plugs/pallet;
5) As customer's requirements.
How to Read Your Spark Plugs
Is your engine running too lean? Too rich? Is there an issue with
oil control or ignition timing? Or is everything just fine with
your engine? Like the mechanical version of the Magic 8-Ball, your
spark plugs may have the answers for you. The trick is learning how
to read your spark plugs.
With help from the spark plug experts at Beyond First Auto, we’ll
teach you how to diagnose minor tuning issues or potentially major
engine problems by examining your spark plugs. Check out the images
below, courtesy of Spark Plugs, and get ready to do a little light
reading the next time you pull your spark plugs.
Appearance: A light tan/gray or brownish color, along with very
little electrode erosion, indicates optimal operation conditions,
including a healthy engine and correct spark plug heat range.
Appearance & Symptoms: The electrodes—center and ground—are
covered in an ashy coating. As a result of this masking of the
electrodes, your engine may experience a misfire. This build-up of
combustion deposits can eventually (but not usually) fill in the
space between the two electrodes.
Possible Causes: Oil leaks, poor fuel quality.
Wet and Dry Fouling
Appearance & Symptoms: Dry fouling (top) appears as sooty,
black build-up. Wet fouling (bottom) has a wet, sometimes oily
appearance. Both conditions can create poor starting and misfiring.
Possible Causes: Depending on whether the spark plug is coated in
oil or fuel, wet fouling can be symptomatic of a compromised head
gasket, poor control from your pistons’ oil control ring,
valvetrain problems, or an extremely rich condition. Dry fouling,
or carbon fouling, is often caused by an overly rich condition, and
the problem may lie with your air cleaner (clogged) or carburetor.
Other possible causes could be low compression, vacuum leak, overly
retarded timing, or improper spark plug heat range.
Appearance & Symptoms: Lead fouling can only occur in
applications that use leaded gasoline, such as racing engines. Lead
fouling generally shows up as yellowish brown deposits on the spark
plug’s insulator nose. Lead fouling can cause your engine to
misfire only at high-rpm and under hard acceleration.
Possible Causes: This condition commonly occurs when gasoline
contains too much lead; however, because spark plugs are changed
frequently in racing applications, lead fouling has become less
Appearance & Symptoms: The insulator around the center
electrode may be broken (see left) or the ground electrode may be
bent. Again, you will likely experience misfire and some power loss
under these conditions.
Possible Causes: If the insulator is broken, it may be the result
of sudden thermal expansion or thermal shock caused by extreme
temperatures or temperature change. Detonation is often the culprit
and can be caused by an extremely lean air/fuel mixture,
drastically advanced timing, improper gasoline octane rating.