Every now and then, somebody requests info on setting-up Webers,
and I've been meaning to provide the following reference.
The following data were extracted from the Moss Triumphtune
Performance Manual.
For a given carburettor type, the different columns represent
increasing degrees of tuning. As a guide, these would pertain
to camshafts called "Road", "Fast road", "Sprint", and "Race",
respectively. (There are too many chices of cam profiles to get
into, here!)
For some "Road" camshafts, there are no Weber carb recom-
mendations, as they find that up-tuned or larger SU's are
adequate.
If there are only 2 columns, these probably refer to "Road" and
"Competition", respectively.
2500 cc (3 X 40DCOE)
--------------------
choke 28 30 33
aux. venturi 4.5 4.5 4.5
emulsion tube F16 F16 F16
main jet 120 120 125
air jet 175 180 185
idle jet 50F9 50F9 50F9
pump 35 35 40
back bleed 0 0 0
Up to 1500 cc (2 X 40DCOE or 1 X 45 DCOE)
-----------------------------------------
----- 40DCOE ------- 45DCOE
choke 28 30 33 33
aux. venturi 4.5 4.5 4.5 4.5
emulsion tube F16 F16 F16 F9
main jet 115 115 125 190
air jet 165 155 165 175
idle jet 45F8 45F8 45F9 45F9
pump 35 35 40 40
back bleed 0 0 0
1300/1500 cc (2 X 40DCOE or 1 X 45 DCOE)
-----------------------------------------
-------40DCOE-------- 45DCOE
choke 28 30 33 33
aux. venturi 4.5 4.5 4.5 4.5
emulsion tube F16 F16 F16 F9
main jet 115 115 125 190
air jet 165 155 165 175
idle jet 45F8 45F8 45F9 45F9
pump 35 35 35 40
back bleed 0 0 0
Up to 1147 cc - 2 X 40DCOE (?)
(Road and Comp)
-----------------------------------------
choke 28/30 33
aux. venturi 4.5 4.5
emulsion tube F16 F16
main jet 115 120
air jet 150 160
idle jet 45F8 45F8
pump 35 35
1850 cc OHC (2 X 40DCOE)
------------------------
choke 33 36
aux. venturi 4.5 4.5
emulsion tube F16 F16
main jet 120 160
air jet 160 210
idle jet 50F8 55F8
pump 35 50
back bleed 0 20
2000 cc, 8-valve OHC (2 X 40DCOE or 2 X 45DCOE)
-----------------------------------------------
---40DCOE--- ---------45DCOE--------
choke 33 36 32 34 36
aux. venturi 4.5 4.5 4.5 4.5 4.5
emulsion tube F16 F16 F16 F16 F16
main jet 195 165 140 135 165/195
air jet 210 180 210 220 230/250
idle jet 50F9 50F9 55F9 55F9 55F9
pump 55 55 45 50 50
back bleed 0 0 0 0 0
2000 cc, 16-valve OHC (2 X 40DCOE or 2 X 45DCOE or 2 X 48DCOE)
-------------------------------------------------------------
---40DCOE--- -------45DCOE------- ---48DCOE---
choke 32 36 34 34 36 42 42
aux. venturi 4.5 4.5 4.5 4.5 4.5 4.5 5.0
emulsion tube F16 F16 F16 F16 F16 F7 F16
main jet 145 155 130 125 160 145 165
air jet 155 170 200 195 250 165 180
idle jet 50F9 50F9 45F9 50F9 55F9 55F9 65F9
pump 40 45 50 50 50 55 45
back bleed 0 20 0 40 40 0 0
My engine ran well with with their exact recommended set-up,
although I'm sure I could squeeze out more power (and, hope-
fully) more bottom-end torque, if I experimented with a
dyno-tuner. Some guys in my club race Dolomite Sprints with the
48DCOE's; they won't idle below about 3,000 rpm, and have broken
a few drive shafts!
Don't run out and order parts until you get independent confir-
mation; the cost adds up pretty quickly!
Allen Nugent
Graduate School of Biomedical Engineering
University of New South Wales
Sydney 2052 Australia
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