I recently performed the Adventure tank swap on my 2005 R1200GS. There's many wonderful descriptions of how to do this, particularly SQD8R's super thread and Hall of Wisdom submission. SQD8R's R12GS with Adv Tank Rob's GSA Tank on a GS Gros Buck's thread. NewEnglander's thread. I notice that this topic doesn't come up very much anymore. Perhaps because R1200GS Adventures are fairly common nowadays, and folks who want the large tank just buy the Adventure instead of the GS. But I'm starting to see more and more Adventure tanks, at very good prices too, on eBay and Craigslist. So I thought I'd tweak SQD8R's instructions a bit and fill in a few gaps so ya'll don't have to read through a bunch of threads to find the specific answer you're looking for. Here's my starting point. A 2005 R1200GS, with a Russell DayLong seat, standard BMW crash guards (not the GSA versions), and GSA panniers. And here's the finished bike. Let's get started. First the revised Parts List. SQD8R's list is wonderful, but a few part numbers have been superceded, a couple are incorrect (BMW's fault), and I've added a few that were missing. Fuel tank ring wrench -<s>161021</s> 83300493639 superceded Fuel tank - 16-11-7-676-458 Side Panel - 46-63-7-694-967 Side Panel - 46-63-7-694-968 BMW decal (2) - 51-14-2-291-869 Bracket 46-63-7-673-255 Bracket 46-63-7-673-256 Adventure right side cover 46-63-7-699-717 Adventure Sucking Pump 16-11-7-694-106<o></o> Bolt (2) 06-32-7-651-211 Gasket 16-11-7-677-883 Fuel Filler Gasket - 16-11-7-654-903 O-Ring - 16-141-183-543 Screw M5X1 (2) 06-32-7-651-212 Screw M5X2 06-32-7-657-966 Rubber Mount (2) 16-11-7-694-114 Nut (3) 46-63-7-658-638 Note:Bracketed numbers indicate a quantity greater than one (1) Additions to Parts List Screw - (2) 07-11-990-04-901 (M8x40 countersunk screws for front tank mounts) Washer - 16-11-230-9560 (for one of those countersunk screws) Body Nut (2) - 61-1313-72-033 (to replace one pair of the Dzus fasteners) Screw (2) - 06-327-657-966 (to replace one pair of Dzus fasteners) You'll also need some Oetiker clamps for the fuel lines. BMW part numbers are included, but you can get them from McMaster-Carr much cheaper. (or use some other fuel clamps) 14mm Clamps (2) - 16-121-176-918 for fuel lines 12mm Clamps (4) - 16-141-183-085 for vent hoses Deletions from Parts List Screw (2) <s>07-11-9-905-650</s> The BMW Parts Fiche lists these screws (M8x95) for the front tank mounts, but it's wrong. These are too long. Rubber (2) <s>46-63-7-700-744</s> These are the cushions to prevent the side panels from rubbing on the tank. I can't figure out where to put these. So I didn't. YMMV. ---------------------------- OK. Let's get started. A few pics of the parts we bought and some prices (list. You can get them cheaper.) The ring wrench. $82 The o-ring for the sucking pump. $1.97 The gasket for top fuel cap (fuel filler). $9.02 Fuel pump (or perhaps sucking pump) assembly gasket. $6.78 Side panel brackets. The right is $10.50; left is $7.94 I suppose there's a reason, but I Here's the wrong bolts for the front of the tank. M8, but 95 cm long. Compared to the equivalent bolt for the R12GS. Told ya they were too long. The correct one: The front tank rubber mounting bushing. 2 @ $4.27 Compared to the equivalent one on the R12GS The Oetiker fuel line clamps. About $1.50 each from BMW. 25 for $10 from McMaster-Carr. Some replacement fuel hose Two $%&#@^*** BMW Roundels for the tanks, at $25.18. Oh, these are larger than the ones on the GS side panels, so you can't (practically speaking) reuse them. BMW is sneaky, in addition to greedy. The sucking pump (the one for the GSA tank is on top). About $125 :eek1 The tanks. ----------------------------------- Getting started on the existing tank removal. Pic of the "virgin" GS bike. I removed the side panels. Drained gas from tank, while tank was on the bike. Unplugged vent lines and gas return. Unplugged electrical connections and fuel pump discharge to throttle bodies. I removed tank (and beak) With the GS tank (the small one) resting in a plastic container, I started removing the major connections to the tank (gas cap and flange rings). In retrospect, I should have left the tank on the bike until I'd removed the gas cap and the fuel pump. Having the tank bolted to the bike give you more leverage when you're removing the gas cap and flange rings. But no matter; proceeding the way I did was ok. I removed the fuel pump assembly first. I placed the flange ring removal tool on the ring. It's sorta obvious how it works. You can see how the slots on the tool fit the protrusions on the ring. Ring comes off. I had to pry the fuel pump assembly off its flange. And I pulled the fuel pump assembly out of the tank. You can see the gasket hanging in the above pic. This gasket is replaced during reinstallation. Removal of the fuel pump assembly can be done independently of removing the gas cap and sucking pump assembly. This is not the case during re-installation; ya gotta go in a certain order; more on this later. Next I removed the gas cap. And took off the top tank cover. Blue on my bike. Then I removed the gas cap internals. I used some white tie wraps to make sure I could re-tie the hoses to the correct nipples (what's the correct term?) To remove the Oetiker clamps on those lines, I used a dremel tool to grind them off. Nippers could also have been used to just cut them off. I then started on the sucking pump flange assembly. I removed the flange ring, same as on the fuel pump. Then pulled off the assembly. Those two hoses off to the right are the same hoses that connected to the fuel cap assembly. One of those hoses has the white tie-wrap attached to it. In the above pic, I had already disconnected the sucking pump from the white assembly. Here's a closeup. After pulling out the sucking pump, I reconnected it to the assembly, so you could have a pic of it. You can sorta see how it connects, even though the o-ring is showing. You can see the sucking pumps for the GSA (top) and the GS (bottom) in the following pic. The GSA pump needs that longer white tubing so it can be placed at the bottom of the right lobe of the tank, to "suck" the fuel into the left lobe, where gas feeds the actual fuel pump to the engine. At this point, the GS tank is empty of everything except some minor traces of gasoline. I tipped the tank over and tried to collect as much of the gas into a gas can. I then started installing the tank components into the GSA tank. In retrospect, I performed this out of order. I should have started attaching the empty tank onto the bike, checking to make sure I had all the appropriate connectors. Besides, once on the bike, I would have had more leverage to screw on the flange rings (fuel pump, and sucking pump). But I didn't. Onward through the fog. 1st I installed the fuel pump. After I had it good and tight, I had to take it off. There's no way to sure the sucking pump is installed correctly if the fuel pump is in the way. Not only does it block your view, but it interferes with the placement of the sucking pump discharge lines. Then I installed the gas cap assembly. I shouldn't have. I needed to install the sucking pump itself first. I left the gas cap assembly in place while I adjusted the sucking pump hoses into position. :whew You all following me? The correct sequence is: - install sucking pump and position it (and its discharge tubing) in the right place in the tank (both right and left lobes) - connect sucking pump to the sucking pump assembly and screw assembly into its flange - connect gas cap assembly vent tubing to sucking pump - install fuel pump assembly and screw it into its flange I didn't do it that way, but it ended up ok, after I'd redone it a few times. After positioning the sucking pump in the tank, I placed the gas cap assembly and routed the gas vent lines through the tank so I could connect them to the sucking pump assemble. Here's a pic showing the hoses sticking out. This is ready for the sucking pump assembly. Here's the sucking pump and the vent tubing connected to the assembly. Note I the fuel clamps I used. What can I say? I didn't have the correct Oetiker clamps, so I used what I had. Remember, do as I say, not as I do. Here's more proof that I didn't have the correct Oetiker clamps. And I was out of small fuel clamps. So I improvised. These vent hoses do not hold any pressure, so I used wire to clamp them on. Oh, the gasket shown is a new one. The cap assembly didn't want to stay centered over the bolt holes. So I cut the heads off M5x40 bolts, and screwed them in to the threaded assemblies. I was then able to align the gas tank cover and fuel cap without any trouble over the bolt holes. Here's the installed fuel pump assembly. And here's the sucking pump assembly. A problem arose, though. Notice the fuel return hose isn't long enough to reach the quick disconnect. You can see me trying to stretch it, but it won't reach. I added a short length of fuel hose to make it reach. With the correct Oetiker clamps. ------------------------------------------------------- Next came in installation of all the tank brackets. This was a bigger PITA than I expected. The nearest BMW dealer is 40 miles away. If I was missing a part, and they didn't have it in stock, a 2 or 3 day delay was a surety. First, some of the brackets on the bike needed to come off. This one, and its partner on the other side came off. Here's a bottom view of the standard GS tank. I ended up needing both of the rear clamps off that tank. I had to remove a piece off the clamp in the 2nd photo. Don't worry, it'll be obvious when you try to attach the side panels. The piece with the Dzus bracket needed to come off. I had some spare M8x40 bolts lying around, so I used them to temporarily hold the front tank bushings in place. Note the long (and wrong) bolt discussed previously. Front brackets were installed on both sides. These hold the side panels. An extra countersunk washer is needed for one of the 4 tank bolts (take your pick, as they're all interchangeable). Here's where I added it. Without the washer, the bolt would probably not have held the tank in place. Installing the side panels ended up being a bit more complicated than I expected. The Dzus fastener on the front of the aluminum side panel would not work with the GSA side panel. Here's a pic. So I had to go back to the BMW dealership and order the correct bolts and nuts to hold it in place. They're included in the above parts list. The good news is once they're installed, no more Dzus fasteners to come loose. Installing of the BMW roundels is easy. Stupidly expensive, but easy. You don't need an explanation. Trust me. If I had been in a worse mood, I might have sent these damn $25 roundels back, and used some SOLAS reflecting tape instead. Jeez, BMW. Could you possibly screw us any harder? I forgot to mention that placing the GSA tank on the frame is a bit more difficult than the GS tank. I needed to take the air intake "snorkel" off, else the tank wouldn't go on. I similarly had to remove the snorkel to take the tank off. The snorkel can be installed with the GSA tank in place. This isn't that difficult. You need to watch out for leaks. DAMHIK. I found it after I'd filled up the tank with gas. It was coming from the sucking pump assembly. It was a good one, too. I drained some of the gas out of the tank, and removed the assembly. I coated the gasket with some motor oil (Mobil 1 20W-50 V-Twin oil - gosh I hope this doesn't start another oil thread), and retightened the flange ring. No more leaks. I've since coated the fuel pump gasket with oil, similarly. That's pretty much it. Here's a few pics of the finished installation. If I had to the another install right now, assuming I had all the correct parts, it would probably take me 3 hours to complete. This install took probably about 10 hours of actual wrenching time, including fixing leaks and removing parts that I installed in the wrong sequence. It's no doubt a more complicated install than the equivalent GSA tank onto an 1150GS (which I also did). Not to mention that the 1200GS install requires more expensive parts to complete. I guess that's progress. Or BMW designing for increased financial returns. Whatever. I filled the tank with 2 gallons of premium gas from a gas can in the garage, then drove 2 miles to a gas station, where I added just about 8 gallons. Seems that I have over 9.5 gallons of capacity in my system. Wow.