Replacement spark plugs must be the same size as the original (same hex size, diameter, thread pitch and length), and have a similar “heat range” (hot enough to resist fouling when the plug is cold, and cool enough to resist pre-ignition when the plug is hot).
Furthermore, are lawn mower spark plugs interchangeable?
The spark plugs in both types of engine work on the same basic principle. ... Some automotive and lawn mower spark plugs may be interchangeable, but many others are not because of physical differences.
Also question is, what spark plug does my mower take? Ideally, most automobile spark plugs use a thread size of about 14mm thread why those of lawn mower range between 10 to 12 mm. Because of these differences in thread sizes, they just won't fit into the same hole or the unit in which the plug is to be fit in.
NGK 6619 Iridium IX Spark Plugs snagged the top pick in our spark plug comparison because they offered the best mix of high-performance, fuel efficiency, durability, and dependability. Featuring an iridium construction, these high-quality spark plugs provide a longer lifespan than copper and platinum spark plugs.
Spark plugs that are gapped incorrectly can cause an engine to miss, or run erratically, especially during idle. The incorrect spark plug gaps can cause uneven firing of individual spark plugs and delay engine combustion; both of which can cause an engine to miss or idle erratically.
For most racing applications, you usually want the plug gap to be between 0.020 and 0.040 of an inch. Most engine builders seem to settle around 0.035 of an inch. Factors such as the type of ignition you run, cylinder heads, fuel and even timing can affect how much gap will work best for you.
What is the difference between rc12yc and rc14yc spark plug? The higher number is a slightly hotter spark type plug. The RC14YC4 is now the standard plug for the 990/992 Generac engines. The 999 in the new 16-22kW Evolution (7000 series) units and older 20kW units are still using the cooler RC12YC4 plugs.