Carb leaking after turned off

Hello forum,

When ever I turn off my falcon it gets really "fumey", it smells like straight gasoline, its like it floods itself upon shut off... I don't know the parts of the carb that well but it more-less pukes up a little gas in spurts after shut off. Its a holley carb & i'm told its too big for my 170 engine & is a problem i inherited with the vehicle. Any thoughts/suggestions?

Thanks!

J0sh

Install a "Metal" inline fuel filter before the fuel pump!! Then replace all rubber fuel lines!! Then remove carb , clean it & install a "NEW!!!!" needle & seat!! Its bypassing the fuel pressure in the line & flooding carb (likely) as seat & needle likely have some trash under them or needle isnt closing properly!

after it is hot, take the gas cap off quickly and see if there is pressure coming out of the tank,,,,,,when its running, squeeze off a rubber fuel line till it dies,,,,,,then start it and see if the gas flushes any dirt out of the needle and seat,,,,,these vans dont have any emission systems on them and the gas just sits in the bowl,,,,,,,and the heat in the doghouse just boils the gas,,,,,, put a fan with a timer under the floor which  cools the radiator, carburetor, doghouse, you,,, and blows the fumes out until everything cools down,,,,,,,,

Have you examined the carb when it's doing this? The seals can seep on the bowl and what not through the gasket(s). Esp w/ a holley. If that is the case, tighten the screws gently. Keep in mind the state of the van when new. It wasn't a problem. It's definitely not right and fixable. Gas fumes/vapors are extremely dangerous. Good advise above. Replace your needle and seat, check out your float, check it's positioned to spec. Give everything a good look over and rebuild the carb yourself. Disassemble it and buy one of those cans of brerrymans "carb dip" for $20 and put a new kit in it and do the set up. Change your plugs, replace your points(use dwell or at least a feeler), reset the initial timing with a vacuum gauge. Advance it until it's at it's highest vacuum with the vacuum advance(LOM actually) disconnected/plugged etc, and then turn it back a bit to the sweet spot. Or do it by ear. Hook it back up and enjoy. You don't want to run it to hot but your 170 will wake right up with a little tune up.

https://www.carburetor-parts.com/1940-Flooding-Trouble-Shooting_ep_653.html

https://www.carburetor-parts.com/Holley-1940-Technical_ep_343.html

https://www.carburetor-parts.com/Holley-1904-Technical_ep_320.html

Other things that happen are radiators and engines get plugged up with crap, minerals and so on. These are old, questionably maintained vehicles. A lot if not most of the old copper radiators in these vans are past their lifespans. Barelysized and clogged with shit. There's no internal cleaning that won't eat the copper, but they can withstand that if in good shape in general. At least once. But you have to wonder how clean they get. i've worked on well fed geothermal systems whose coils were shot in a few years and could be cleaned once. Convection currents and heat transfer though the water/block/radiator should be adequate. Even after shut down. Physics and thermal dynamic law haven't changed from 61. And they had hot summers back then to. Have no doubt, for all the talk it hasn't changed that much. The optimum operating temps of these motors is 190 or more. I think the stock thermostat is 190 and it's 190 for a reason. They thought they could get away with it. Hotter=more efficient. The motor runs best at 190-220 but dissipation and heat soak are hard to deal with, esp when airflow is at a minimum. To be clear, we're talking about a low revving engine that on it's best day has no more than 90-100 rwhp, most probably @ 60-80(and get's 20-30 mpg)

Do you still have the heat shield and phenolic spacer under the carb?

Its an age old complaint as the heat percolates the fuel when you shut off the motor. Made even worse when people insulate the doghouse and then no where for the heat to go but the top and to the carbuerator.
 Years ago I recommended using a boat bilge pump air blower under the truck and connected to a thermostat and a relay to blow cool air over the carb and move the hot air out of the doghouse. Many people have been using it and seems to work very well.
 Ford in fact using a manifold and air pump on the later 300 motors with a warning label on it that says it is designed to run after you shut the truck off. This on an F series truck with a lot of room for the hot air where ours doesn't. 
 Also a large thread and disscussions about the fuel pressure being higher than it  needs to be as well as also using a pressure regulator that bleeds the excess pressure back to the fuel line and or the gas tank after shut down. Any increase of the fuel pressure in the line from expansion that normally washes the oil off of your rings before you re start the motor (ugh),,, relieved and not forced against and overriding your float.
OLDSKOOL