Would it be fair to assume that "M" would be the better needle for more power
at lower speeds and better fuel economy at higher speeds? Or am I looking at
this too simplisticly?
Eriks.
Paul A Asgeirsson wrote:
> About the two sets of needles you have.
>
> Assuming that the engine you will be contemplating their use on as a 1275
> dual carb model some info is below.
>
> There are 16 or 12 steps on each needle with the following diameters:
>
> STEPS AAC M
>
> 1 .089 .089
> 2 .0855 .0855
> 3 .0835 .0832
> 4 .0811 .0808
> 5 .0788 .0785
> 6 .0765 .0763
> 7 .0742 .0745
> 8 .072 .0726
> 9 .0698 .0707
> 10 .0676 .0688
> 11 .0655 .0669
> 12 .0631 .065
> 13 .061
> 14 .059
> 15 .057
> 16 .055
>
> Up to step 6, the M provides more fuel due to its smaller diameters.
> Beyond that it would run leaner.
>
> The AAC is listed for the 73-74 Mark III Midget as the standard needle
> with the use of blue springs. There are no weak or rich needles listed
> for those years
>
> The M is listed as the rich needle for the 1969 MG1300 or the 1971 MG1300
> Mk II, or their corresponding Austin marks, again with blue springs. Blue
> springs are what are used in nearly all Spridgets. It also is listed for
> some engines other than 1275 dual carb jobs, but I don't think that info
> is of any particular use.
>
> Paul
>
> PAsgeirsson@juno.com
>
> On Thu, 10 Dec 1998 10:19:27 +1100 Eriks Skinkis <eriks@netspace.net.au>
> writes:
> >I have two sets of 1.25" SU carb's. Looking at the needles one pair
> >has
> >the later type spring loaded needles stamped "AAC" while the other
> >pair
> >has the earlier type fixed needles stamped "M".
> >
> >Is there much difference between the "AAC" and the "M" needles, would
> >one be better than the other?
> >
> >Thanks,
> >Eriks.
> >
> >Midget '70
> >
> >
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