I think I just turned the key on, let the electric fuel pump prime it, then start. Of course, I haven't owned the 2100 for over 10 years now, so just going by memory. I also think there is a fuel filter underneath tractor near transmission on left side, need to remove deck to change it. My BX1870 has the 2 dinky clear filters, going to be updating that in a week or so.... to bleed the line, I believe you just crack the nut on main line going into injection pump under hood, crank it until you stop seeing bubbles and a steady stream of fuel, then tighten nut. Make sure you have some rags....