Shawn---I started to write a long reply to your post, regarding the fuel
monitor picking up the bump in richness at 3,000. It got so unweildy I
quit writing. There's too much for me to say for this type of forum, so
I'll just hi-lite a couple of things.
Yes, you can find out exactly what part of your needles is responsible
for this increase in richness. You'll need to see where the air valve(s)
are, in relation to leaving the bridge. This area of the needle will
have to be wider. There are temporary ways of "thickening" the needle,
one identified. From there, you can do to the SU chart to see if a
commercial is available.
First, I would "paint up" the needles now being used, to see if these
mods make the monitor show the results you desire. It's very tricky,
because you have to do the same thickening on all three of your needles.
(Unless you have isolated each carb with its own 02 sensor)
For a really good book on this, pick up a copy written by Des Hammill,
on "How to Power Tune the SU Carburetor". (The same principles apply to
the ZS carb).
More on this, if you wish...
Dick
|