I have owned a 2008 K1200GT from new and do my own maintenance. The bike now has 122,000 miles. It is very similar to the K1300GT in almost all respects.
Getting all the body work off is petty basic, lots of screws is all.
Pulling the radiator you'll do well to buy the clamping tool to remove the radiator hose clamps.
Because...you have to pull the radiator to get to the spark plugs and the valves.
The coils are a ***** to get off the plugs even with the proper coil remover tool. The original white coils chipped easy, real easy.
Checking the valves is standard stuff...once you get the radiator and the valve cover off.
So far, even with the cam chain on our bike jumping two teeth, the valves have not needed any adjustment. An adjustment would require the cams to be pulled.
DO make sure the cam chain anti jump piece is installed. It's a recall and free if it hasn't been.
Filling the radiator can be done without an Air-Lift though the Air-Lift tool with a air compressor makes it a bit easier.
Bleeding the brakes is mostly standard. I have swapped out all the bleeders with Speed Bleeders. Makes it an easier one man job. (See the comment below about the GS-911.)
Draining the oil tank with the straw is a bit slow, and getting the straw off the oil tank can be a real PITA.
The newer rear drives on the K13s do have a fill and a drain. My '08 didn't have a drain, I had to drop the rear drive every time I did a rear drive oil change.
The clutch on our bike got to the point I couldn't get her into neutral when running and stopped. Once that began, the clutch got a bit sticky. It took a new basket and clutch pack to fix it. That was the only big expensive I had because neither the OEM nor the extended warranty covered the clutch.
The older rear drives let dirt in. Wanda and I tried to ride through an Haboob and packed the rear drive with sand. The replacement drive was $2,300 and was covered by our extended warranty.
There is a recall on the fuel pump housing on Beemers past 2005. Need to be sure that was done.
A GS-911 is a very valuable tool that will aid in properly bleeding the brakes, resetting the computer, checking which brake pads are worn and then reset them, and a bunch of other stuff. In my opinion it is a must have tool if you have a modern computer driven bike.
And...order the DVD OEM Repair Manual. Lots of torque settings and stuff to pay attention to.
On the other hand...if you don't do you own maintenance...never mind
Our 2008 K1200GT is our bike of choice for long distance travel. We just got back from Texas for the MOA Getaway in Kerrville, 1,800 miles round trip. The GT averaged 40 mpg two up with six days of clothes.
If BMW did another K12/K13GT, it would probably be our next Beemer.
Deryle & Wanda Mehrten
Sierra Vista, AZ USA