Im currently having some issues with a 2100 autolite 2 brl.

Im hoping to find someone who is good with old carbs.

The whole story is-- I wanted to replace the original carb. since someone had removed the choke assy. I purchased a rebuilt 2100, upon installation, it blew raw fuel out the top vent holes. I checked the carb., all inside seemed correct. could not get it fixed. Bought another rebuilt 2100----installed new fuel filters before and after the carb., installed a good pressure regulator (set it at 3 psi), installed the new rebuild-----and it blew fuel out the top--profusely. Engine is stock, installation of carb. and regulator was correct. The latest carb. I actually saw run on a test fixture (with no leaks).
Something about my installation isn't right--but I haven't been able to figure it out. Im an old hot rodder who grew up with carbs----but this one has me puzzled.
Help, Help------please!!!!! thanks guys,,,,,

 

The above should read INSTALLED NEW FUEL FILTERS BEFORE AND AFTER THE FUEL PUMP!!

 

Are you running an electric fuel pump or mechanical? Never hear too much about needing a regulator with a mechanical fuel pump.

What year is the car/carb? Is the same as what came off the car?

http://www.mustang-s.com/years/1966/..._carb_2100.htm

Also, here's a cutaway diagram to give you a look on the vents/air bleeds to let you get a better idea of what's going on. It's been years (like 20) since I've touched a carbed motor.

 

Fuel out the vent holes means the bowls are overfilling. You just need to figure out why.

Either your float adjustments are way off, the needle isn't seating properly, or fuel pressure is overpowering the needle and blowing it off the seat.

One of the nice things about the 2100/4100 series carbs is that you can run them with the top off, which allows you to make adjustments without having to reassemble the carb before testing.

Pull the top off and start by adjusting the float height (I don't have the spec handy, but I bet someone here has a rebuild kit with the spec). If the fuel level keeps rising too much, see if you can manually seat the needle while the engine is running by gently pushing it down. If the fuel level continues to rise, you have a problem with the needle/seat. If it doesn't, either your float level is still incorrect, or your fuel pressure is pushing the needle off the seat.

 

Thanks for the replies guys,

First, the regulator was mainly a precautionary troubleshooting device. It is a stock 289 w/mechanical pump.
I also subscribe to the theory that leaks of this nature are caused by dirty fuel or over pressure. Since I had a similar problem with two diff. carbs. I was trying to eliminate the dirty fuel possibility as well as over pressure.
Got back into it today, verified clean fuel, then I verified fuel pressure hadn't changed (had to go borrow a pressure gauge again.) Only leaves one thing-- internal adjustment or bad needle valve. I finally reached the seller to see if the warranty would be voided under the circumstances. He agreed to let me pull the top and check. Float level was correct-- so, I spent some time blasting it with air.
Problem solved, so I guess something must have been under the inlet valve.

Still doesn't explain the issue with the first rebuilt carb.--but at this point Im willing to cut my losses and enjoy the fact that one of them works.

I want to thank you guys go your help and concern---I saved the links for future reference. thanks again,,,

 

Having read the entire thread I agree about float levels, possible dirt, etc.. but what unsettled me the most was the regulator. If you're running a stock mechanical pump the regulator is an unnecessary "something else to cause trouble" device.. I'd remove it. It's just not necessary with your setup.

 

Sounds like dirt in the fuel line or dirt in the tank. Unless you clean both you will probably be experiencing the problem fairly soon. Dirt and varnish will go through a pump but cause havoc with the needle valve.