Looks like most are reading this post incorrectly. The OP is looking for a filter to nest inside the tractor fill neck to eliminate the debris that may fall in while opening the fill cap. Mr funnels, funnels with screens, in line fuel filters for fuel delivery systems will not work. The BX filter noted is what he is looking for but simply does not fit his machine. I have not seen anything that fits inside the measurements that he has posted.I did a quick search here with out luck.
I have a L2501 and find the area around the filler neck and fuel tank cap is a magnet for dust, dirt and debris. I often times rely on friends and family to help with refueling due to the location of the fuel tank filler and find that as helpful as they are, they do not have the same level of concern that I do for keeping my fuel as clean as possible going into the tank. My B7100 came with a pre-filter and think this is a feature that should have been included on the L2501 and like series.
Can someone recommend a pre-filter screen that for sure fits the L2501 and will use the factory fuel cap?