Carb flooding cylinders 1 and 3 only, why??

This is a fresh built .030 440 with Eddy heads, a M1 intake and 750 Speed Demon.
I am trying to get my motor running for the first time. I keep having problems with cylinders 1 and 3 flooding with gas. The motor will fire and run maybe 20 seconds, then slow down and quit. It might fire again and sputter and no start. I pull the plugs and turn it over and gas will squirt out of 1 and 3.
What would cause the carb to give excess fuel to those two cylinders? I am not using the choke and I am not reefing it. I am using an electric fuel pump and the gauge says about 4 to 5 psi. The fuel is level in both float bowls.

P.S. First, I thought the head gasket was leaking water into the cylinder---I re-torqued the heads, and it still flooded-- I held a cup up to the #1 spark plug hole and it put maybe two ounces of gas with no water into the cup.

Any ideas are greatly appreciated.

Sounds like trash in the needle seats,remove and clean/blow them out. Is this a new carb? If so you may want to remove the bowls and check for trash as well. If you have a known "good" carb it might be a good time to try it.

Yeah, its a new carb... I pulled the bowls to check the float settings and look for trash before starting it, however I didn't look at the needle and seat for the primary...will check that next.

Thanks.

Try this,turn the electric pump on and while it's running shine a light down the carb with the engine off. Do you see fuel dripping from the boosters?

Another think I'd be worried about is fuel contamination of the oil. Oil diluted with fuel makes a poor lubricant. I'd check or change it if in doubt.

I turned the pump on and looked down the throat with a light...no fuel coming in from the boosters.

I will check the oil for gas...I got a bottle of cam break in lube along with Rotella... I was hoping to get the cam broke-in before changing the oil... oh well..
Thanks again.

Adjust the idle mixture screw on the driver's side.

I'll bet the flooding on 1 and 3 is a symptom. Look at your intake runners, is one and three lower than 5 and 7? Probably is. Sounds like the carb has an issue on that side and it's showing up on one and three.

Supercuda-- I looked at the manifold and the bottom is level, It is an M1 single plane.

At the moment, I am going to dust off a Thermoquad that I rebuilt years ago and see if I can get it to run without flooding... I will deal with the other carb later.....Will let you all know how it turns out.

Had the same problem on my set up. Check your power valve if it has a hole in it it will leak gas and run into the cyl happend to me but on cyl 2 & 4. Also check your fuel pressure maybe gettin too much if so add a regulator. I also changed the seats although the carbs were new the needle & seats were junk.

Is there good spark getting to those cylinders?
Maybe the fuel is not getting fired.

I got it running using the Thermoquad. No flooding in any cylinders anymore.
For some backround, the motor is on a borrowed homemade test stand. I am trying to get the motor broke in and then it goes to get dyno tuned.
It ran great for a few of minutes while I was trying to set the idle for break-in. Then when everything seemed to be going well...the positive battery cable fell on the header, and in a spectacular cloud of sparks and smoke, caused a dead short and melted the negative cable to the battery terminal.

The Demon is on the bench and will get played with later.