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Old 04-20-2013, 10:54 PM
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Once you get this sorted out the accelerator pump shooters may need tweeking.

Need another AFR trace at part throttle cruise. 40++MPH so you are truly on the primary main jets and not still driving on the idle circuit.
And then a nice 2nd gear WOT pull ,, rug it from low cruise/part throttle drive road speed to 6000rpm. in 2nd gear.
( first gear is too much wheel spin)

You then need to work on one area of the primary jetting at a time.
you cahnged both the cruise and the WOT at the same time.
one change at a time ,,, only. Work on only one circuit/driving mode at a time.

Then need a idle AFR trace at idle (neutral) idle in gear,, and then idle at 1500 rpm and idle at 2000 rpm and idle at 2500rpm
( in the drive way in neutral no load) ( idle and off idle transition circuit)
set the idle with a vacuum gauge for best idle quality, not afr. It will be RICHER than 14.7:1 at idle.
carbed engines idle at a AFR of 12.5:1 to 13.8:1. The priority is best idle quality and best idle manifold vacuum, not a specific idle AFR. Give it what it wants at idle...or you will never get the off idle correct.
Then: the off idle transition should be in the +/- 14:1 afr zone. 13's are fine at the transition.
This is off idle 1200 rpm to 2000++++++ rpm light throttle, before rth primary mains start up.

REMBER with dual quads you are mostly driving around ON THE IDLE CIRCUIT and off dle circuit
until you get really going (road speed and rpm)

You need to be able to identify which circuit you are driving on and tune only that circuit.
A vacuum gauge really helps.
Do not try to tune /correct the part throttle tune (primary rod lean step diameter ) and the WOT tune at the same time. (rod tip and main jet)

GET a vacuum gauge

Last edited by F-BIRD'88; 04-20-2013 at 11:22 PM.
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