T H E  O L D  G R E E N  B E E M E R
RIDING A 1974 BMW R90/6 FLAT TWIN



AIR FILTER SERVICE, NO MORE ELBOW WRESTLING



Reaching the air filter element involves too much screwing around. The
left
side carburettor needs to be loosened and taken from its rubbers at both
ends. This is NOT very handy to say the least, so I came up with this.






Way too much work, agony and bad language ( R 80/7 in picture )
And there are throttle, choke cables and crud as well!





Cropped stainless steel air ducts, looks odd but makes air filter service a lot simpler.
The rubber that connects to the air filter box can now slide down over the duct.
The duct can than be taken off by loosening the carburettor intake side.
So that's 3 clamps to loosen and the carb can stay where it is !
No more fumbling with a cranky plastic elbow anymore.





CAUTION : The duct must have a loose fit between carb and air
filter
outlet to prevent metal to metal abrasion caused by vibration.



REACHING FOR THE AIR FILTER FROM THE PORT SIDE?





Taking the air filter housing off the right hand side can be tricky, you need a
rather thin ring spanner to undo the nut holding it down, a truly clumsy
design. You better fabricate a clip
and a thick spacer like shown
here,
and use another hex bolt and washer instead. Now the
cover can be slid off and on, just as the left hand side.


O, YES ...

On a " normal " boxer, the engine breather hose has to be disconnected
and pulled inwards as well. On this bike the hose goes outboard via

a hole in the starter motor cover and feeds into a catch bottle.
I've plugged the breather hose opening in the filter cover.





Breather cap rotated over 90 degrees, venting in catch bottle.






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