Toyota Universal Weed Wacker Spark Plug L7RTC NGK BPMR7A For Small Engines

Denso W22MPR-U 

Autelite:XST2974DP / 2974

Packing:

1) 1pc in a small box, 10pcs in a middle box, 200pcs in an export carton;

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.

Normal

Appearance: A light tan/gray or brownish color, along with very little electrode erosion, indies optimal operation conditions, including a healthy engine and correct spark plug heat range.

Deposits

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.

Lead Fouling

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 common.

Breakage

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.