Oil filler cap cover the hole in the engine where engine oil is added
Look at the engine on your lawn mower. If the engine has an oil filler tube or a "hole" with a cap on it where oil is added to the engine, it is a 4-cycle (4-stroke) engine. If there is no oil filler tube or place to add oil to the engine, then it is a 2-cycle (2-stroke) engine and the oil has to be added to the fuel.
Maybe you added too much oil? Overfilling can cause just as many problems as being too low on engine oil. Be sure to check the dipstick after adding oil.
If it is a 2-stroke engine, 2-cycle engine oil is added to the gasoline. If the engine is 4-stroke, regular 30W motor oil is used. To tell if your engine is 2-stroke or 4-stroke, look for a spout where oil is poured into the engine. If there is no spout, then the engine is 2-stroke and 2-cycle oil must be added to the gasoline.
On one side of the engine, there will be a cover marked "OIL" or a symbol like an oil can. This is where engine oil is added.
If the engine has an oil sump and an oil filler spout, it is a 4-cycle engine. On a 2-cycle engine, oil must be added to the fuel.
Engine oil is added to an engine to decrease friction between moving parts. The oil forms a lubricating film between the surfaces, reducing wear and heat generation.
added to much oil If you added too much oil that can and will cause engine wear and damage. If you are loosing Oil it is either being burnt, or it is leaking. If it is burning oil it is normally caused by worn piston rings.
Coolant added to engine oil? It would run but it would do serious damage to internal parts of the engine and drastically shorten the life span of the engine. Don't run it! Have the oil and filter changed NOW.
That would depend on whether the engine is a 2-stroke or a 4-stroke. You can determine by looking for an oil filler spout or filler cap on the engine. If it has one, the engine is a 4-stroke and the oil is added through there. If it doesn't have one, the engine is a 2-stroke and 2-cycle oil must be added to the fuel in the recommended ratio.
An engine needs lubrication to reduce friction and prevent overheating of the internal parts. Oil is added to the gasoline in a 2-cycle engine because this type of engine does not have an oil reservoir.
A gas only engine has a spout where oil is added to the engine. If there is no spout, then it is a gas/oil engine. FYI - gas only engine is a four-stroke (four-cycle) engine and the gas/oil engine is two-stroke (two-cycle).