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NEEDLE PROFILE for SU Carburetors - CB-120

SU needle calibration diameters are designated at 1/8-inch increments starting at the top mounting shoulder. Those positions are call "stations". The MGA pushord engine originally has H4 carburetors (1-1/2" throat) with .090" needles and 13 designated stations. The standard needle profiles are shown here. Other SU carburetors may have needles up to 2-inches long with 16 stations. The needle number will be found on the upper shank of the needle. Install the needle with the shoulder flush with bottom of the air float piston (and try to avoid positioning the set screw on the numbers).
MGA 1500
 LeanStdRich
Sta.4GSCC
1.0890.0890.0890
2.0850.0850.0850
3.0814.0815.0810
4.0785.0785.0780
5.0761.0755.0750
6.0737.0725.0725
7.0714.0700.0698
8.0692.0675.0670
9.0668.0650.0640
10.0645.0625.0610
11.0620.0600.0590
12.0610.0575.0550
13.0600.0550.0520
SU needle diagram
MGA 1600 & 1622
LeanStdRich 
AO6ROSta.
.0890.0890.08901
.0850.0850.08502
.0820.0814.08103
.0793.0785.07704
.0766.0755.07405
.0737.0725.07106
.0705.0696.06857
.0673.0666.06608
.0640.0636.06339
.0608.0606.060510
.0576.0577.058011
.0544.0550.055812
.0510.0520.053013

Click for a page that will display the needle profiles for comparison.
SU needle comparison
Click for a spread sheet with more needle numbers tabulated.

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