BMW R1100GS: Fuel Filter & Fuel Line Quick Disconnects

The below repairs, replacements, and what-not have all been done by me on my 1995 R1100GS. This procedure applies to all R850/1100/1150 type BMW motorcycles with or without ABS. This procedure, with some minor modifications, also applies to the K1200RS and similar generation bikes. Do not attempt any of these procedures unless you're confident in your skills - however limited - as a shade-tree mechanic. Don't send me hate mail if you mess something up!!

Replacing Fuel Filter, Fuel Line & Fuel Line Quick Disconnects

1. Remove both seats and side cover. You do not need to disconnect the battery. Locate the tank arm bolt, electrical connector for the fuel pump & gauge, and existing fuel lines.
2. Disconnect all of them. Also disconnect the fuel vent lines (not pictured). Fuel tank arm requires 8mm hex. My bike has a captive nut (welded to the frame) but yours might not - don't let it drop!
3. Remove tank and carefully clean away any debris on or near the fuel pump/filter plate, like any bugs that have been lusciously preserved by the hot engine.
Fuel filter replacement

4. Put the tank down so that the plate is on the bottom. If you've drained the tank of enough gas, you won't make a mess. If you haven't, you're going to need to open one of the fuel lines and drain more gas. Be careful - remember it's gasoline [i][b]fumes[/b][/i] that are flammable.

5. With paint or a permanent marker, make two distinct marks across both the plate and the tank.

6. Loosen all 6 fuel plate nuts by a turn or two (8mm socket). BE GENTLE. These things are on studs, not bolts, and if you break a stud, you are well & truly screwed. Once they're all a little loose, start taking them off one at a time, keeping some downward pressure on the plate until they are all off.

7. Gently wiggle and pull the entire assembly until it's free of the tank. BE CAREFUL. The fuel gauge float arm is long and swings easily. You will have to kind of work things around to get it all off. Don't lose the thin vent lines inside the tank, and don't jerk them free either. Note the rubber o-ring.

8. Set the plate down and pull the vent lines off. If you've already had a canisterectomy, it doesn't matter which vent line goes back on to which fitting, but if you still have your charcoal canister (look behind right side passenger footpeg), mark one line and fitting with paint or permanent marker. Once the vent lines are off, remove the rubber o-ring and install the new one. You can re-use the existing o-ring if you set it out to dry in the sun for a few hours.

9. Note the flow arrow on the installed filter and place new filter next to the plate with its arrow pointing the same direction.

10. Use the needlenose pliers to spread apart the squeeze clamps on the fuel hoses on either end of the fuel filter. Pull the fuel filter free from the lines (gas will spray so watch your face) Use the cap that came with the new filter to plug the old filter end so gas doesn't run out both ends.

11. Slide new clamps onto the hoses before installing the new filter. Once the filter is in place, place and secure the new clamps.

12. Installation is the reverse of removal. Use the needlenose pliers to work the tank's internal vent lines back onto their fittings - that way you don't need to source new clamps. Use your previously made marks to properly align the plate. Be particularly careful and attentive in placing the o-ring in its groove. [b]CAREFULLY[/b] and in a star pattern reinstall and gradually tighten the fuel plate nuts. They do have a torque value, but I don't remember what it is - I hold the plate down firmly to keep the o-ring in its groove, then snug the nuts down slightly. Once they're all snugged, I go around in a star pattern, turning each one a little bit until they are all solidly tight. Don't overtighten them though - you could snap off one of those studs!

Note that I did not reinstall the ground wire. When the R1100GS first came out, it had a plastic tank that required a separate ground wire. My GS had its tank replaced under warranty (as many of the '95s did), but the techs at that time left the ground wire. It's been disconnected for well over 6 months; I took this opportunity to remove it completely.  
Fuel lines & Jiffy-Tite quick disconnects

If you're doing this maint, you've probably got the apparently breakable plastic quick-d's that people seem to be having a lot of trouble with. I have never had a problem with mine, but now I'm all paranoid about them breaking while I'm out on the road.

13. Do one line at a time. I did the bottom line first, the one I planned on installing the 45-degree QD on.

14. Use the needlenose pliers to open the existing clamps on the plate end and remove ONE fuel line (careful - gas might spray out!). Put a new clamp on the FI hose, install it onto the fitting, and secure the clamp.

15. Open the clamp on the bike end of the fuel line and remove that length of the fuel line. Put the tank back on the bike (a good time to check for leaks around the fuel pump plate o-ring by shaking the tank vigorously) and mark how long the line needs to be to reach the other fitting (the one you just removed the fuel line from). Also mark approximately where you want the QD to go.

16. Take the tank back off. Cut the line at both marks.

17. For the length of hose that's going on the bike side of the setup, put 2 clamps on that hose, install the line, and secure one clamp. Work one end of the new QD into the other end of the hose (twist & push), then secure the other clamp on it.

Picture note: here the old, plastic QD is on the top line; the new, aluminum Jiffy-Tite QD is on the bottom line.

18. Slide a clamp on the tank side of the line, install the other end of the QD (the 45-degree end in my case for the bottom line), and secure the clamp.

19. Repeat steps 14-18 for the other (top) line. Take care to reverse the direction of your QDs to prevent getting them mixed up in the future. Also take care not to stack them one on top of the other - stagger them. Finally, be careful in your routing of the new fuel lines so they don't displace anything, rest on anything hot, or rest on anything that could vibrate through them.

20. Reinstall the tank; connect both fuel lines, both vent lines, and the electrical connector (use a dab of dielectric gunk to displace moisture). Turn the key - listen for the whine of the fuel pump priming, then start the bike! If it works, you're done - go fill up your tank, clean up your kit, and take a shower. If it doesn't work, you have to backtrack through everything you've done and find the error - start with the electrical connector.
 
That's about it! After I finished I decided to shorten the bottom line to get it up off the telelever pivot. That's when I discovered that you don't really NEED the clamps on them - I had to cut the line at the end of the QD, then had to cut it in smaller nips to get it off the QD. I left the clamps on anyway - redundancy sometimes soothes the mind.

The Jiffy-Tite QDs are expensive (parts + shipping from Daytona BMW was $117) but their all-metal (aluminum) construction with no sliceable o-rings means there's simply no chance for failure. There's no button - that entire gold-colored collar slides back to disconnect. You can't reconnect the fittings without sliding the collar back again.

I had planned on replacing the fuel lines inside the tank as well, but once I opened it up, I could see that they were new, or at least about a year old. The fuel filter in there was about a year old too, obviously installed by the previous owner, but since I was in there, I replaced it anyway. Now I know exactly when it went in (15,990 miles). I'm that guy!