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.
Likewise, do all Honda mowers use the same spark plug? 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.
Yes there are different plugs for different engines. Usually you need the engine model on your mower, and take in the old spark plug to the hardware store. Ask for someone to help you find the right spark plug and tell them your engine model and mower model.
Check the gap on the new spark plug before installing it. A new plug will often come pre-gapped to match your specific engine, but use a spark plug gauge to verify that it matches the manufacturer's specifications.
A dirty or fouled spark plug can cause your lawn mower to not start. It can also work itself loose, causing issues. If the spark plug appears to be seated correctly but the engine doesn't start, a new one may be in order.
Spark plugs are typically located on the back or side of a lawn mower engine. Look for a short wire that's about 1/4-in. -thick leading to the top of a short, cylindrical protrusion from the engine. If you're not sure where the spark plug is, consult your owner's manual.