Tell us more about the engine you are asking about….Are you referring to the “scintered filter” in the glass fuel bowl? Perhaps the threaded scintered filter in the 3hp fuel tank? There are no real substitutes for these items… You could put a simple inline fuel filter in the fuel hose if the engine uses an external tank. Adding an inline filter to the 3hp is more of a project, because this engine has a copper fuel line that runs from the tank to the carb….
If you are trying to add an extra filter to compensate for a dirty/rusted/fouled fuel tank, you will probably have no success….The tank needs to be either cleaned or replaced…