The float assembly may be gummed up or stuck. When the fuel bowl fills up, the float lifts and shuts a needle valve to keep fuel from coming into the bowl. Think of it kinda like the water shutoff inside in your toilet tank...if that float got a hole in it or got stuck down your water would just run and run. On a toilet, it just goes down the doody pipe but on a carb it's got nowhere to go but out the vents and other orifices. Sometimes you can rap the bowls on the side with a screwdriver handle or something and get it to come loose. Other than that it's not too bad to take the bowls off and check them. Those two large screws and jam nuts on top are for setting the float level which will set the bowl fuel level higher or lower before the needle valve shuts.

 

Chances are you are gonna find some junk on the needle valve or seat. It doesn't take much, hope you have good eyes.

 

Alright sweet, So take the bowls off and inspect for crud, where are the "needles" going to be located? Do any of you have a diagram of any sort?

 

Start off with the simple stuff with the bowl on the carb. The needle and seat-look at how many threads are
showing so you get the fuel level close to where it was. Remove the needle and seat and spray compressed
air in it with the pointed tip held open. Before you screw it back in, lube the rubber O ring with a tad of oil so it doesn't tear.

Note: fuel level height is performed with the engine running. If you don't have a clear site plug on the side of the bowl for setting
the height then remove the side screw and adjust the level so fuel is just sitting at the bottom if the threads. Test it by nudging your
fender and gas should trickle out. NOTE: do not drive the car with clear site plugs cause they will melt. They are only used for setting
the fuel level.

These are from my web page.
Remove lock screw while holding adjustment nut. (note on assembly-turning this nut CW lowers the float and turning it CC will raise it.

Then lift nut off and note where the paper gaskets are.

Then unscrew the needle/seat with your fingers, it's 1 piece.

Fuel level site plug. Note tin gasket.

 

Nice pictures Mark.

 

I love pics, they tell the whole story.

 

Wow thanks for the great info! I got the bowls off and cleaned them up, I noticed one bowl kind of gets jammed if pressed down. Im assuming it probably got stuck while the carburetor was being moved around, when it was off the engine. It's running great now. Thanks for all the help.

 

It's nice when a plan comes together. More info on my Web Site if you need it http://www.nastyz28.com/~copo/holley.htm