D2/D4 carburetor initial settings

I'm getting close to starting the gas engine and need to set the 2 adjustments on the carburetor. It's been awhile since I've worked on one and don't remember where to set them to get started. Any guidance would be appreciated.

Hi Scott,

this thread has the details but both settings appear to be one turn from closed initially. If you have the horizontal main jet screw on your carb, then you first need to verify that the 90 degree tang that transfers the screw's motion to the jet rod is actually a right angle. It's very easy to over-torque and bend. Then screw the adjuster out until the needle seats, then back in one turn. Same for the air screw, which is one turn out from fully in (which is full rich/no air). The other thing I check too is that with the throttle plate closed, the idle "nozzle" which is a plug right where the throttle plate seats in the throat is clear and allows the nozzle see some vacuum. That's where the idle fuel is released into the intake air and is important for good idling - https://acmoc.org/forum/discussion/starting-engine-carburetor-adjustment-late-modle-d-2-zenith-tu4c-carb

Thanks Neil, that gives me a good starting point . All passages were cleaned and verified open. I don't have the offset screw system on this one but am aware of that and have dealt with it before

For any one interested I ended up about 1 turn out for the idle circuit and about 3/4 turn on the high speed adjustment. The 1/2 turn 1 turn in the link will definitely get it started, that's where I started. Neil's suggestions of 1 turn 1 turn will probably get you started and might run good. This is isn't an exact science but it's not rocket science