Well-known member
Heh everyone, Has anyone ever tried the Holley/weber 6520 progressive carb on the 200 or 250, I believe it is the same as the 5200, (32 primary, 36 secondary), but it is a feedback carb, whereas the 5200 is not. Just what is the difference between the two :unsure:: :unsure:: And how do you hook up the 6520 :unsure:: :unsure:: Everything looks the same except there is a solenoid dropping down into the top of the fuel chamber on the 6520.
That sounds interesting. Does the solenoid have a vacuum port?

There is a high mileage circuit that uses manifold vacuum to the float bowl for deceleration and for going down hill. During the deceleration and coasting down hill the manifold pressure actually goes up and is like the choke providing a rich mixture. The idea is to reduce the atmospheric pressure in the float bowl. This ported manifold vacuum reduces the amount of fuel used during these two conditions.

If this is what it is for, I had no idea that the Big Three actually used this idea.

Anyone know for sure?
63Comet, that's quite a coincidence. I just installed a H/W 6520 carb this week. It came out of an 2.2l Chrysler (1984). I believe the solenoid does have a vacuum port that actually gets in the way of my air cleaner. I am not using the port an will probably remove the solenoid. I will try and post some pictures of my setup ASAP. The biggest problem I had with this carb was jetting it just right. It's not perfect, but still functional and performs well.
Alex, what jetting have you got :unsure:: and I believe it takes the same jets as the 5200. I bought these carbs on E-bay, I got 4 of them for $37.00. plus shipping. They need to be cleaned up and probably a kit also. I believe that the solenoid is for vaccuum operation, but I am not sure. The guy I got these from said they were from 2.3 liter engines, he bought a race car and these came with it. I also got 1 other carb with them and I am not sure what this one is either. It says motorcraft on it, and it looks like it's 32mm primary and 40mm vaccuum secondary. I would like to try this on the 200, but it has more s--t attached to it, several solenoids and pull-offs and vaccuum lines running here and there.
The 6500 Holley Weber series is referred to as the "feedback" type. They were the last of the pre fuel injection carbs used on Ford and Chrysler cars. The solinoid you are seeing used signals from a set of sensors to manage main jet mixture on the run. Unless you have the complete set of sensors, operating correctly, the carb cannot perform as intended. The best thing to do would be to convert it back to the 5200 configuration. Not sure how one would go about this but this site may be useful

I was told by Tom at Stovebolt when I purchased my 5200 that the 6500 series was not easily adapted to autos not set up for them.

Site map didn't work. Try this

Wrong again. Time to get some sleep. Try this

Thanks for trying Steve, but that one doesn't seem to work either. Why can't you just plug off that part of it ? Everything else looks the same as the 5200 except that little pocket in the carb body and the solenoid.
The address is correct. You really need to read this. I dont know if it can be converted but if I understand the operation the solenoid turns the fuel full on without power. Maybe with this full on you could rejet the carb. However, it sounds to me like the solenoid controls the main metering system. Is there a main jet in this carb other than the one the soleniod controls?? Type this address in yourself. I know it works.

There is some interesting info about the 5200 here also.
Steve, I don't believe that's the same carb, that is not the solenoid I am talking about, actually mine looks like it has a diapraghm down on the bottom end. It has 2 main jets just like the 5200, primary and secondary. Also it is the 6520 not the 6200 series, I believe they were used on late 70's early 80's vehicles with 2.3 liter engines. I haven't checked out the jets, but I will and I think they are the same as the 5200's. Thanks for your help. Still searching.