There's a good website :www.RealOEM.com, make sure you have the last 7 characters of your bikes VIN, put it into the search box, and all of the exploded views, will have the part numbers that your bike left the factory with. Also it will tell you the month and year your bike was assembled, which is necessary for some part numbers, because of a change in design or availability to BMW during production runs. It's best to get familiar with the parts catalog, at least here in the US, as support for these old bikes is quite lacking, I don't know if that is the case where you reside or not.