How to change your venturies
To change the venturies, first remove linkage from carburetors. 
Next remove the carburetors from the manifolds.  Be careful because
the fuel lines are still connected. 

Rotate the carburetor and
disconnect the fuel lines.  Use caution and cap off your fuel lines. 
Verify they do not leak any fuel.   Rotate carburetor to the back and
disconnect the accelerator arm from the throttle body.  You may
need to use a flat screwdriver.  Careful not to bend the pump arm
and the throttle body lever. 

Now rotate the carburetor back to the
front.  Then tip the carburetor just enough to remove the ( 2 ) screws
underneath the throttle body.  Don't tip it too much as fuel may start
to leak.

  With the throttle body removed, you will need to  back-out the
set screw on the left side of the carburetor (located just above the
"BROSOL IND BRAS" script).  You do not need to remove this screw just back it out about three turns.It is not designed to be removed.

The venturie should  fall out.  If not you may need to help it.  To reinstall, 
make sure the dip in the venturie is faced towards the back of the carburetor.
The venturie can only go in one way.  A way to confirm the venturie is in
correctly is it will not be able to spin due to the dip at the top of the venturie. 
Finally, follow the above directions in reverse. 
<-- Venturie