Hello, Just spotted your question in the fuel thread about F650 water pumps, so here goes:
Inside the left hand crank case cover is the waterpump and clutch. The pump has no bearing, it instead runs on the seal that separates the water and the oil. This is pure cheap and nasty design, of which Rotax, Aprillia and BMW should be heartily ashamed. At something between 1000 and 30000 miles, said seal will fail, your oil will go chocolate brown and the motor will run about 100 degrees warmer as it is now air/oil not water cooled. Like a game of stone scssors paper, the steel shaft that wrecked the seal will then be scratched to uselessness by the engine casing. You then need to buy a £40 kit from Motorworks/Motorbinns (£70 from BMW) and replace the seal and shaft before you can purge the coolant and change the oil. This takes under an hour and can be done with the engine in the bike, so it's a home job if you get your hands dirty.
If your oil is chocolate brown do it now. If your bike is over 20000 miles and never had one, get the kit in and do it when you've time. If you are 500 miles south of Gibraltar you have two choices; set fire to if there and then or ride it in air cooled mode. The second plan will warp the head and result in repairs that would cost more than the bike is worth unless you can get a spare engine. Don't ask how I know this

The chain gang has lots of info on this. It isn't a big issue if you catch it, are prepared and aren't halfway to Dakar. The other F650 build issues are the VR/heat trap and the chocolate construction used for the sump plug drain hole if I remember correctly. Nothing to worry about so long as you have fixes and/or avoiding action planned.
Andy
PS: Almost forgot to add what I've added to every BMW thread since 2004: Alan Jefferies BMW of Shipley UK are useless ****ers.