Do it once and do it right.
I think you are doubting the machinery too much.
You had a fuel problem, and now its playing up again and you are mentioning spark again.
Personally i would not even contemplate removing a filter unless the tap was out of the tank.
Take the tap out. Put your thumb over the hole, put some fresh fuel in the tank rinse it round and shake it all about then tip it out on the nearest weed patch. Get the tank squeaky clean.
If theres even a hint of water, a dot of milky goodness, air the tank out, put it in the sun and dry it out.
If its hot you could also use some warm soapy water. You can stuff a rag in there as well and poke it about with a screwdriver and pull it ouf with some pointy nose pliers.
Bone dry without a hint of dirt or grass is how you want it.
While you are wating you can sort the filter, refit and put the tap back in the tank when its chean and dry. Or just fit a new tap with filter.
