Enrichen transition circuit

[midnightrider1818]

Question for the holley gurus, I have a 850 double pumper on a stock late model low compression 440, msd distributor and performer rpm intake, stock cam, when I cruise at 60 im running on the transition circuit and running lean, how would I go about enriching the transition circuit with keeping my idle afr good thanks

 

[midnightrider1818]

Just a picture for reference

 

[ckessel]

Not the answer to your question, but your air filter setup is quite undersized. Like trying to breathe through a straw while you're running.

 

[R/T Boy 67]

The cruise AFR is adjusted by the main jets, air bleeds etc. The main jets will have no affect on the idle circuit. The full throttle AFR is adjusted by the power valve restriction. This is of course over simplified.

 

[Geoff 2]

He says his transition is lean. Transition fuel is supplied by the idle jet. Increase the idle jet in 0.002" increments & retest. Idle mixture gets RE-adjusted via the mixture screws.
You could also try raising the fuel level slightly about 0.100" before drilling any holes.

 

[451Mopar]

Need to test either without the air filter or the filter spaced higher away from the fuel bowl vents. If the air filter lid is too close the the bowl vents it can mess up the carb metering.
I think if you had a lean spot at tip-in in the transition then enlarging the Idle Feed Restriction (IFR) size would help, but you mentioned lean at 60 MPH in the transition circuit so I think using a smaller Idle Air Bleed should work better to richen the transition and quicken getting into the main circuit.

 

[AR67GTX]

Maybe my sense of carb operation is out of wack but I can’t see running on the transition circuit at 60 mph? If that is true however, restricting the idle air bleed as 451 Mopar suggested would be the easiest way. I’ve done it on an older Holley by inserting wire in the bleed to reduce it by 30%. But again, I’m doubtful it’s running on the transition circuit.

 

[R/T Boy 67]

The OP wrote cruise, at 60 mph. I don't think the word transition was used correctly, but midnightrider could clear it up.