<VV> Leaning Out the Midrange...Continued

[NicolCS at aol.com]

<snip>The results show the following A/F 
results: Left Bank = 12.8, Right Bank = 12.1.  Both readings are a few clicks 
rich 
from the ideal stoichiometric fuel mixture  of 14.7. As the main jets are 
already .049s, and the main jet size has little  (if any) effect on midrange 
A/F 
ratio, my next step is to open up the air bleeds  on top of the venturi 
clusters. The bleeds will be adjusted  upwards using numbered drill bits, and 
will be 
opened up just one or two  numbers at a time (between retesting A/F ratio).
Observations or suggestions? Mike Mauro<unsnip>

Well, here's one thing to consider...  14.7 isn't the "ideal" afr unless you 
are a catalytic converter.  There are really three "ideal" afr numbers.  The 
ideal "cruise/economy" number is around 15 to 15.5.  The ideal "power" range is 
12.5 to 13.5.  And yes, the ideal number that leaves no excess fuel or air 
for best catalytic converter performance is 14.7.  I'd recommend jetting for 
high 14s/low 15s at cruise and around 13:1 under high loads.
Craig Nicol