Changing the Fuel Filter on an R1100RS
Here is the procedure to change your R1100RS fuel filter. It took me about 90 minutes the first time....but hopefully, things will go more quickly for you!
Purchase the following before you start: a new fuel filter, a new sealing O-ring for the fuel pump plate, and two standard BMW fuel line clamps just like the ones used on the fuel lines by the right side throttle body (point to these on your bike if your parts jockey doesn't understand). Let your sealing O-ring lie out for a few days before starting the job.....I didn't and had trouble later.
Let the fuel level run down, way down, so low you don't think you can make it back to the gas station. It still won't be low enough so you might want to siphon out from the top as well. Get as much fuel out as possible. Drain, swirl the bike, drain some more. OK?
Remove the left and right fairing panels, the seats, and the right fuel injector cover. Unplug the right fuel injector wire and the fuel pump harness. The fuel delivery hoses run behind the cross-over throttle cable, and most people will have too many fingers to keep all that stuff plugged in. Remember that there are also two screws tying the upper fairing to the gas tank, and two little screws holding the left and right inner panels (the ones with the rocker switches/RID) to the gas tank. Those screws all must be out.
Remove the screw holding down the back of the gas tank, and keep track of the grommets used to fill the gap between the frame and the tank. They like to fall out....
Unplug the vent lines right next to the airbox, and loosen both fuel line clamps. The top fuel line is holding the fuel....when you pull it, you will need to drain into a gas can until it stops, otherwise there will be a tremendous mess. When it is done draining, remove the other hose and lift the tank off the bike.
I laif the tank on a towel on my garage floor, right side down. Loosen the pump plate, carefully pull the inside vent lines off the plate, and gently rotate the whole assembly out. Hold the assembly with your right hand, and use your left hand to guide the fuel level sender and fuel pump screen through the hole in the side of the tank.
I carried the fuel pump/filter works to the bench. Anyone familiar with a K-bike will recognize everything here except the fuel filter is held in with compression clamps. I pried those clamps off, pulled the hoses from either end, removed the old filter and inserted the new one, and tightened the works down with the aforementioned screw-type clamps.
Look at the fuel level sender rod while you have the parts out. There should be an E-ring type circlip holding the float to the rod, but some of the early bikes were missing these and had their floats bobbing around the tank rather than registering fuel level.
I carried the assembly back to the gas tank. The O-ring must be pressed down into the groove, the vent lines forced back on the plate, and install the plate exactly as removed. Start all six screws, and tighten in a cross pattern. I tilted the tank back up after this operation to try and get the O-ring to leak. After 30 minutes or so, nothing had come out. I would suggest doing this as well to avoid having to re-remove the tank to fix a leak.
Reinsert the fuel tank, and the lines pretty much fall into place. I added some gas to the tank because you don't want to run these roller cell fuel pumps dry for any reason. I would also coat the fuel injector and fuel pump connector pins with dielectric grease to deal with the moisture and corrosion that the bike sees daily in some cases. Reinstall all body work and all the screws you removed.
Tighten the clamps on the fuel lines and reattach the vent lines by the airbox. Start the bike, check for leaks, and if all is well, ride the hell out of it for another year!