Air Filter Cartridge – BMW R51/3

[comet]

Michael, the plunger frame bikes had three different air cleaners. The most popular and the one probably on your R51/3 is a Knecht. It looks similar to the ones found on the R50 and R60s but flatter. The filter element is the permanent type that should be cleaned and oiled ocasionally and is partially visable when assembled. The filter measures 14.5 cm o.s. dia. 6.0cm i.s. dia and 3.0 cm high. Good luck finding one...........Comet

[Micha]

Thanks a lot!

[VBMWMO]

Hello friends, my bike is missing the cartridge, there's just the empty housing, and I will be thankful for some information:
First of all, what kind is fitted? Is it a wet type or a dry one? Any modern car or motorcycle matching cartridge outside, i.e. from the automotive market or only an original will fit? Where can I find an exploded drawing of it, as in the auxiliary catalogue there is only the complete one showed, with no parts listing?
Thanks in advance, Michael.