Ford 640 Carb Problem?

[Old Tractor Newbe]

Working on a friends 640. It ran when parked 2 years ago. Tried starting it last fall. It would turn over but not start. But a shot of carb cleaner and fires right up. Getting fuel into carb ok. Cleaned and rebuilt the carb. It was definitely gummed up inside. I was confident problem found; NOT. Carb fills up with gas but dosen't seem to move fuel out of fuel bowl. Full choke while cranking but no sign of flooding. Will start on spray. Tore it apart today, gas in the bowl, and everything clean and passages open. What am I doing wrong?

 

[old]

Working on a friends 640. It ran when parked 2 years ago. Tried starting it last fall. It would turn over but not start. But a shot of carb cleaner and fires right up. Getting fuel into carb ok. Cleaned and rebuilt the carb. It was definitely gummed up inside. I was confident problem found; NOT. Carb fills up with gas but dosen't seem to move fuel out of fuel bowl. Full choke while cranking but no sign of flooding. Will start on spray. Tore it apart today, gas in the bowl, and everything clean and passages open. What am I doing wrong?

When you clean/rebuild a carb you need to soak it for 24 hours or so. Spray it out with spray carb cleaner. Poke out the passage ways with a piece of wire or as I do I use a torch tip cleaner tool to poke out the passageways then spray it out again and blow it out with air. Then repeat the last 3 steps 3 or 4 times. Plus with the carb drain plug out you need a steady flow of gas that will fill a pint jar in less then 2 minutes

 

[showcrop]

Sounds like a rubber tipped float valve needle. The rubber tipped ones replaced the brass ones maybe twenty years ago and they are prone to stick to the seat. The common practice that a lot of us have had success with is to tap the bottom of the needle with it in the seat, with the end of the handle of your screwdriver. This compresses the rubber mating surface slightly and then it is less likely to stick. When installing a new float valve you never discard the brass needle if it has one.

 

[Butch(OH)]

Definitely still has passages plugged. I quit using carb cleaners as all the old good ones are NLA. Now I use a pot over a fire with nothing but water and a bit of citrus cleaner and boil it for a while. This loosens up deposits but you still need to prod the passages and poke them out, followed by the air gun. The main jet passages are pretty easy to follow up from the bowl through the jet to the Venturi.

 

[Old Tractor Newbe]

Working on a friends 640. It ran when parked 2 years ago. Tried starting it last fall. It would turn over but not start. But a shot of carb cleaner and fires right up. Getting fuel into carb ok. Cleaned and rebuilt the carb. It was definitely gummed up inside. I was confident problem found; NOT. Carb fills up with gas but dosen't seem to move fuel out of fuel bowl. Full choke while cranking but no sign of flooding. Will start on spray. Tore it apart today, gas in the bowl, and everything clean and passages open. What am I doing wrong?

Thanks for the replies. You made me question my confidence in the repair. Found a cutaway diagrahm on the internet and led to more thorough cleaning of all passages. Bingo! Think I found the problem.
Blew compressed air in here--it goes around and around-- and gas mist comes out there! (Sorry)