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.
Beside this, does it matter what spark plugs you use in lawn mower?
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.
Its center electrode should have a flat top. ... If the spark plug is in good shape but is black with carbon or wet with gasoline, then a good cleaning with a wire brush and adjusting the gap between the electrodes may be all that's needed for the spark plug to restore power to the mower.
Typically, the consensus among the mechanical engineer community is that a spark plug for a lawn mower will last up to 25 hours of use. Some users simply prefer to replace it every mowing season as a part of their yearly lawn mower maintenance.
Your local Toro service dealer is the best place to get the correct replacement spark plug for your machine. Bring your machine's model and serial number so you're sure to get the right plug. Today's spark plugs come pre-gapped, but it's a good idea to double check this before installation.
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.
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.