[varmint]

Originally Posted by jhynesrockmtn

From the bmwmotorcycletechinfo.com site

"There was no oil filter such as a paper pleated filter, as there is on the 1970+ Airheads. On the /2, the oil from the oil pump was 'filtered' by sending it into closely separated plates or plate and backing, that were part of the crankshaft assembly. One plate is called a slinger, where the harsher of the contaminants would be deposited into a hard layer along the edge of what was actually a shallow cup. The capacity of the cavities was limited. If the slingers were not cleaned at reasonable intervals (you will not think the mileage reasonable! ...30,000 miles!) , the slingers could fill-up, clog the oil passageway, & some very expensive engine parts would be ruined"

Or if the bike has just been sitting too long.