From: davet@void (Dave Thompson)
Date: Tue, 30 Aug 1994 10:24:56 -0500
Subject: fuel filters

After purchasing my used GS, I replaced all the fluids. I flushed
the transmission and final drive oil a second time because they were
especially full of metallic sludge.   I drained the tank to remove any
sediment and to check out the fuel filter.  My '92 GS, as I think with all post
'85 BMW's, has a fuel screen that wraps around a plastic primary fuel intake 
tube and protrudes about 4 inches into the gas tank.  After seeing this,
my fears of getting a clogged fuel strainer in the future were somewhat
alleviated, as I think it would take mud in my gas tank to clog these screens.
I think they are an excellent design.  Because of the length and surface
area that fuel may pass through, and the fact that fuel is free to 
splash and wash away sediment on the screen in the gas tank, I'm not
worried about these getting gunked up.

I found some in-line fuel filters that I really like.  They are packaged
by a company called "Emgo".  The have a cylindrical glass housing with
with chrome plated metal ends.  The ends screw off so that one can access
the cylindrical fuel filter element inside the glass housing.  The fuel
filter element and the spare that comes with the package have a nylon
strainer that is finer than the metal (brass?) stock strainer off the petcock
in the fuel tank.  The things I like about these fuel filters are:
	o Fuel filter element is easily field cleanable.
	o It's easy to visually inspect the fuel filter element.
	o Fuel in the fuel line is clearly visible

I can see the movement of fuel when I turn the petcock or when I turn the
ignition key and the fuel solenoid opens on my '92 GS.  Since installing
these, I've discovered that Shell's premium gas is pink which matches
nicely against my marakesh red tank.  :-)

I think it would be pretty difficult to break the glass housing
even if I dropped the bike on a protruding rock that didn't take out
the head, carburettor, petcock or gas tank first.  I left some extra
fuel line in in case I had to take out the in line filter.

Unfortunately, the replacement filter element I've initially
found has a brass strainer that has pores about the same size as the
stock fuel strainer in the tank making the element non-functional.
However, since the filter elements are cleanable, I'm not sure I'll need
more than the two supplied nylon elements.

I'm not sure if the extra filter is needed around the states since most
gas stations pumps have built in fuel filters anyway.  However, I feel
more comfortable not counting on this.  I'm planning to do some third 
world country touring where they have creative gas pumps.
In Burma, a gas station consisted of a mobile stand that stood about 4 feet
high.  On top of it was a bucket with a petcock and a hose running from the
petcock to one's gas tank.  An attendant would bring over an open vessel of 
measured gas and pour it into the bucket on the stand.  When the petcock
was opened, gravity would force the flow of gas into one's tank.
Imagine the crud build up...

Cost at my local general parts motorcycle shop was $11 x 2 fuel lines.

Dave Thompson
davet@ncsa.uiuc.edu (http://yahoo.ncsa.uiuc.edu/davet/)
'82 R65LS
'92 R100GS
Champaign, IL