R100GS Oil Filter Installation
My GS came to me from the original owner with the paper gasket and steel shim in place. My understanding is that the bike was always serviced by a BMW dealer. Granted, this is second hand information, but if true, it means that BMW dealers are using the paper gasket when they replace oil filters. I've also communicated with Jhed Webster, BMWNA's west coast warranty arbitrator, who said the "official" take is to use the steel shim and the paper gasket. So your mileage may vary! The best recommendation I can make is to refer to this page and make the measurements needed to determine which parts you should use to get the correct compression on that white o-ring. When I followed those directions I found that the canister depth was 4.2mm. By using two steel shims and NO paper gasket, the gap for the white o-ring goes to 3.6mm, well within the 3.1mm to 3.8mm BMW recommends.
For this '93 R100GS, here's how it goes: There's a black square section "O" ring attached to one end of the filter. That end goes in first when you install the filter. Next goes the steel ring, which sets on the little shelf created by the end of the oil canister inside the engine case. I always check to make sure that the old shim has been removed before installing a new one. On top of the steel ring goes the white "O" ring, the one that is round in cross section. Now put the black "O" ring, the one with the rectangular cross section, into the groove in the underside of the oil filter canister cover. That's the thing with the two pipes that go to the oil cooler. A drop or two of oil helps hold this "O" ring in place. Push the oil filter door down onto the oil filter, and you should feel some resistance before it bottoms out on the engine case. That means the "O" rings are being compressed, and that's a good thing. Start the three screws into the oil filter door by hand, then use an allen wrench to draw them up a little at a time, working from one to the next until the door is flat against the case. Give each one a final twist up to the proper torque (go 'till they strip, then back off half a turn, er, no, just kidding!).
Don't forget to fill the bike with oil when you're done!