For those that can see the picts, the most restrictive area of the filter is the factory space between the choke flap and where it seats when placed on choke. When the choke flap is in the open position the space/gap between the flap and seat is very narrow, how narrow depends on which type or maker of filter you have. I grind some material away behind the choke flap to allow it to open further and can gain close to .250 or 1/4" more opening, this makes some very good gains in these saws. In the pict the areas marked in black, between the two retaining screws and the choke stopper tang get ground away as showing in the mesh filter. The combination of the partition removal and the extra choke opening really does make a difference on the 026 and MS260.