Do it yourself.
The 1150 is a remarkably simple bit of kit, and it's easy to service.
You will find lots and lots of useful info on this site.
Only special tool that may be needed is an oil filter wrench - the oil filter sits up in the sump and is almost impossible to remove without the specal tool.
You will have to remove the bashplate - best to soak all the nuts and bolts in WD40 first.
Do warm up the bike prior to draining the oil.
Do give the oil plenty of time to drain - I pleave it on the sidestand for 10 mins, and then lean it against a wall the other way for 10 mins to completely drain the oil in the heads.
Which oil? As I've already said, the GS is a simple bit of kit, and can literally run on extra virgin! It doesn't demand synthetic oil- it's a luxury. At 12.000 miles, I'd stick with non-synthetic for another service to ensure the bike is fully run in. I use a good quality mineral 20w50, as reccomended in the manual - it runs much smoother than the 10/40 when it's hot. A good tip here is that Tescos sell their own brand of oil which has all of the correct ratings (SJ rating) and is really cheap (£3.00 a gallon!)
Plugs. These are fairly easy - remember to use the tool in the toolkit that came with the bike to remove the HT lead. Many socket-set plug adapters will get trapped in the head - stick with the bike's toolkit plug spanner.
Which plugs? I've stuck with the standard BMW Bosch plugs, but recently, I've seen there are a few threads that reccomend a champion EON2 plug - These may well be worth a try - especially at the price.
A tip here is to put a little smear of copper grease on the plug threads. (Just a little - don't get it on the plug tip or insulator.)
Valve clearence. This is an easy job - follow the workshop manual, and you can't go wrong.
Tips -
DO keep everything spotlessly clean - this is inside the engine, and ang grit will play havoc.
Do change the spark plug hole rubber gasket - only a quid or two, but these do tend to go.
Inspect the rubber valve cover seal when you take it off. Only re-use if it is in good condition - replace it if you have any doubts.
When refilling the oil -
Do use a new sealing ring on the drain plug.
Remember to let the oil settle - These boxers are buggers for holding oil in the heads. You can use the trick of leaning the bike the other way to help drain all the oil into the sump to get an accurate sump contents reading. Be very careful not to overfill.
Gearbox & bevel box oils - These are a doddle - simply remove the drain plugs, and let the oil drain. Remember to use new sealing rings on the oil drain plugs. Fill to level with reccomended oil - again, you will find info on gear oils on this site.
Air filter - easy job - under the seat, undo the cover and replace air filter. While you are there - change it for a K&N or similar.
The remaining items are very straightforward - check battery level, lights, brake pads, tyres etc etc.
If you want to start balancing the throttle Bodies, then there's lots of useful info on this site.
A good tip here is (if you can) be prepared to step away from the bike and come back to it later. Don't do this just before a weekend away - take your time, and don't be afraid to ask someone.
If you need any advice PM me.
