Sorry it is a 4-108. So do i do anything to this as far as cleaning goes? Aster a year it gets kind of dirty and oily.
Jason, the proper maintenance for the intake mushroom and screen filter is to simply soak it in a container with some mineral spirits awhile and then give it a good scrub with a small brush--an old toothbrush will do. Run a pipe cleaner through the tube that the crankcase breather connects to and ensure that it's clean/clear. Then thoroughly dry the thing and give it a wipe with WD40 and your good to go.
The reason the 4-108 has the metal screen is because the engine has a "flame start" system for starting in cold weather. Essentially, when the ignition key is turned to the last detent position just before "start", a small glow plug in the intake is activated and a small valve opened to allow a drip or two of fuel on the glow plug. After 15 - 20 seconds, the plug will be hot enough to ignite the fuel, generating a "little" flame, although, with intake cover/screen filter-flame suppressor removed, it can rise up 4-5 inches above the intake. The mushroom cap and screen, of course, contain this in normal operations. The flame generates the heat needed to ensure starting in very cold conditions. This approach is "old technology", from the 1930's - 40's, but it is simple and effective.
I have been an advocate of the K&N Filter for the 4-108 as friends of ours have had good success with one at reducing intake noise and, through the crankcase vent, lower crankcase pressure and reducing oil seepage around the rear seal. The K&N is made of of a plastic material that is heat resistant up to about 300º F but exposure to an open flame could pose problems. Accordingly, if one is operating in an area where one might need/want the pre-heater/flame start function, the K&N might not be wise. If using one, it would be wise to disconnect the wiring to the glow-plug (but labeled) and put a note in one's engine maintenance log for a potential future owner.