1963 394 ultra high compression, 4 jet carburetor on it. seems like it's idling a bit rich like it's loading up, I have to gas it every now and again to smooth it out. But the major problem is when I open up the throttle all the way it bogs down and will nearly die if it is held open. I cleaned it really well and it had a bunch of trash in it, but it is definitely clean now. It does it much worse when there is a load on the motor, it's almost imperceptible when the car is in park or neutral. It seems to run pretty fine most of the time that the throttle is below the half way point... any suggestions?

 

buy a new carb lol idk man

 

Go to the Wiki section on this site under "Carburetors ",and there's a whole piece on step-by-step rebuild/tuning.

 

When you cleaned the carburetor did you rebuild it, or just spray it with carb cleaner? If you haven't rebuilt it I suggest you do that.

 

I do know what i'm doing with carburetors, the accelerator pump is leaking a little, but I didn't think that it was enough to cause this. All of the needle valves are funtioning properly. There is an issue with the secondary butterflies not opening up on their own, it seems like they are gravity controlled as well as with suction, but on the little cam that operates them there is a stop that doesn't get out of the way soon enough, if I hold it open by hand when the car is revved up, it might help it but it's kinda hard to tell without a load on the engine.

I did not rebuild it, but I did more than "spray it with carburetor cleaner". I didn't think that it needed it other than the accelerator pump, and all that was broken on it is the little boot on the top the actual pumping mechanism works fine as does everything else. The floats were out of adjustment and causing the carburetor to dump fuel into the oil... I guess I won't need to do an engine flush huh?

I was just wondering if anyone else had this problem, and kinda hoping they would say, "oh you have to take the doodad off of the thingy" or something to that effect. I'll try tweaking it some more, but it seems like it's overloading it with fuel, so maybe that accelerator pump isn't as good as I think it is huh?

 

Check your floats. after setting mine with the service manual specs, anytime I took a turn it flooded out. Pulled the top back off the carb, lowered the float level by about 1/4" and all was well. in my experience, I had to lower the rear(secondary) floats a bit more then the front to get rid of all stumbles but now runs great. Float drop needs to be correct too, or you wont get enough fuel in the bowls quick enough to keep up with engine demand at w.o.t.

 

hey, that might be it. I did adjust the floats down some because of the fuel dumping issue, it is more than possible that I over compensated. When I get the transmission straightened out i'll pull the carburetor off and push them back up just a hair. One of them (i can'te remember front or back) was quite a bit farther than the other one, like 1/4 inch or more. I'll check that out and see what's going on with it.