It's a BMW engine for sure

found on bubble visor

Sonic Beemer

found on Dirty Boots

BMW Clubber

found on bubble visor. more on Dirty Boots

1966 R69S

BMW R75/5

found here

1971 R60/5 SWB Cafe racer

more here . Lot of interesting infos.

Larry's Special Ks

You can find whole article about Larrys bikes on
BMW Motorcycle Owners Of America

Where Pictures Speak Louder Than Words

BMW R80/7 by Untitled Motorcycles. "Midlife Crisis" ?

found on 8 negro , more can be found on UNTITLED MOTORCYCLES

BMW R80/7 1979

found on Polish auction site allegro.pl