If you are referring to the screw on canister filter, Absolutely not. Change your oil AND filter every 50 hours or one year, whichever comes first. I strongly recommend a quality brand name full synthetic oil in an air cooled engine as the oil temps can reach over 250 degrees on a hot day. It will only cost around 4 dollars more than regular oil. Avoid Fram filters. Use an OEM, Napa Gold (Wix), Purolator Pure One, Walmarts supertech (champion labs) filters, (not their oil as I have 2 quarts of 5w30 SuperTech synthetic and the add pack has separated after 12 months on my shelf).
Many riding mower don't have oil filters. If your's does it is on the side of the engine toward the bottom and probably on the left side as you sit on the mower.
Does it need to be cleaned and regapped? Maybe it needs to be replaced?
There will be an inline filter on the fuel supply line from the tank to the carburetor
You can get them at any mower shop. Most Lowes and Home Depot stores will carry them also. You just need to know what engine is in the mower.
I believe that deck uses sealed permanently lubed bearings.
If you have a fuel filter on a push mower then its probably the only one in the universe-fuel filters are commonly found on items with engines.
One reason that a lawn mower may begin to smoke is that the oil chamber is too full. Spark plugs that have burnt oil and are not cleaned can create smoke and other exhaust issues.
Air filters are always on or at least very near the carburetor usually in a box or canister
Change spark plug
The most common cause of surging in lawn mower engines is a dirty air filter. It just needs to be removed and cleaned if it is the foam type, It it is the paper type, it needs to be replaced.
The fuel filter is clogged or the carburetor needs to be cleaned and/or adjusted.
There could be a couples of reasons a Toro lawn mower is making squeaking noises. One reason could be the blades need to cleaned. Another reason is the spindle that attaches the blades may need to be greased.