doing a little maintinance on the blower, thb-2510, and could use some help. first on air filter, can i use regular filter oil, even better think i got can of k & n here somewhere, to doctor up before install. and second want to replace fuel filter but need to fish out of tank. what, if any tool works best for this? btw pick up plug but not going to mess with for now, machines runs good, but if know gap, could use for future, thanks.