Topica Loopframe_Guzzi Archive


Subject: Re: Fuel Flow 101

Author: Paul Linn

Date: Apr 11, 2003, 5:51 PM

Post ID: 1712589703


Then I would strip the petcocks and see if the rubbers are torn up and
interfering with fuel flow.

Paul
Midlothian, Va
73 Eldo "Elvira" at a halt in favor of "Daisy"
74 Eldo "Daisy" new project
76 T3 basket of stuff
----- Original Message -----
From: "Keith Ruff" <klru-@fcc.net>
To: <Loopfram-@topica.com>
Sent: Friday, April 11, 2003 8:13 PM
Subject: RE: Fuel Flow 101


 Nope, won't even flow with the cap off. Cleaned up the cap already too.

Keith Ruff
71 Police Ambassador - NJ

3haw-@bluefrog.biz wrote:
 Keith, dirty fuel cap? BOb
----- Original Message -----
From: Keith Ruff <klru-@fcc.net>
To: <Loopfram-@topica.com>
Sent: Friday, April 11, 2003 10:55 AM
Subject: Fuel Flow 101


 I need an education on how the fuel flow works from tank to carb. On
all of the BMW's I had owned in the past, a fuel line from each
petcock
 
 
 connected to a crossover, which then had fuel lines running from the
crossover to each carb. This is the exact same set up on my 71 Ambo.
I
 
 
 
used to also run in line filters on my Beemers but have not done so on
the Ambo. When I opened the petcocks on the Beemers, fuel would flow
through the lines, down to the carbs, and fill all the way up back up
to
 
 
 
the petcock. There was fuel throughout the entire line, either when
running or not running. The Ambo has got me confused. When I open
the
 
 
 petcocks, nothing flows. I can see fuel in the lower lines just below
the crossover, but the fuel will not fill the remainder of the lines.
I
 
 
 
just checked the petcocks, removed the hose from one side and put a
test
 
 
 
fuel hose on it and ran it to a container. Opened the petcock and
fuel
 
 
 was a flowin'. Closed the petcock, let the line drain, then put my
thumb on the end of the hose. Opened the petcock and NO FLOW. So it
appears any air in the line stops the flow. I then tested the right
side petcock while the left side was disconnected so air could escape
and it flowed perfect, but gas would not flow when I put my thumb over
the open end of the left side fuel hose. Can I deduce that the
petcocks
 
 
 
are not functioning correctly? Should the petcocks allow air pockets
in
 
 
 
the lines to escape up into the tank, or is that the job of the carbs?
I squirted some carb cleaner into the carb vent holes but that did not
change the situation, still no flow out of the petcocks when the lines
were reconnected. Does this sytem not want fuel all the way up the
lines to the petcocks, but rather just enough in the lower lines to
feed
 
 
 
the carbs? Does it let air escape through the carb vent holes when
the
 
 
 carbs need fuel, thus letting fuel flow out of the petcocks? I am
confused at the operation. I am not sure if I am worried about
nothing
 
 
 or if I have a fuel flow problem. Please educate me.

Thanx!

Keith Ruff
71 Police Ambassador - NJ

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