SU problems (I think)

[Dennis Nicholas]

Its running too weak as revs rise (wrong needle) and nine flats down is too much making it rich at bottom end, damping is not the main issue here, you can get an SU to work well with very little damping at all, in fact that exactly what is needed in some racing situations..  I suggest reading up about how SU's work and needle selection there is a lot of good information available. I have reached a stage where I can not be bothered repeating it all as the same issue comes up again and again with lots of confusing advice for the unwary.

Well said Ian.  It is always best to understand how something works before messing with it.  A little time (sometimes a lot!) pays dividends in the long run getting things right.
A read up will show dimensions of needles and can thus even help in modifying ones needle using a file where too weak at one section.
Of course some equipment can be too technical for a lot of people, but at least a bit of effort does usually pay off.

Dennis