My 444 won't stay running except on starter fluid.

Thanks for taking the time to read this.

I have an International Harvester 444 (gas) that I inherited with my farm. It ran great last year, but towards the end of the season, as the tractor warmed up, it would sometimes act starved for gas.

This spring I rebuilt the carburetor (a TSX 896 model) with a rebuild kit. It never really got over the symptoms and still acted the same way. I've been told a number of things: It is electrical, so I changed the points, coil, cap, condensor, wires - still same problem.

I was told it may have weak gas flow, so I drained gas and checked flow through the electric pump to the carburetor, and have a solid stream (ran a couple gallons to make sure).

I had a crack in the exhaust manifold (on these older ones, the exhaust/intake are 1 piece) so I replaced the manifold.

I finally took it to the shop and had them look at it. They were backlogged 3 weeks, so for a simple checkup and ultimately them fiddling with the single adjustment screw and using some carb cleaner on the carb, it cost me $200

When I got it back, the tractor ran for about 2 hours and then same symptoms came back, but worse. Now it won't start without starting fluid. I drained the gas to make sure no water/condesation was in it. I can squirt gas or starter fluid into the carb and the tractor will run as long as I fuel it. The new manifold seems tight and sucks up gas well. The carb float appears to be working as I can open the drain plug and a constant stream will run out. I did clean out all the holes in it (again) to make sure no debris clogged anything inside the carb.

I've literally pulled the carb apart about 5 times looking for anything I may have missed. I've went through every hole in it with pipe cleaners (some are at 90 degree elbows so my pipe cleaner won't seem to go through all of them).

It just appears this thing won't suck gas up from the main jet on the carb, and I must say, marvel schebler carbs are dirt simple, so I just don't know what to do with it short of buying a new carb.

Any ideas on what could be causing this problem?

Thanks (I just want my 444 back to the way it was last year)

If it runs on SF, two things come to mind. 1)something is plugged in some fashion - junk, or adjustments or 2)a gasket/seal is leaking air.
Since you"ve cleaned it (if cleaner passes thru those 90s and any screens, I"ll assume it"s clean), the problem might be limited to adjustments - like float clearance and "jets" - or reused gaskets.
Re-check adjustments and use new gaskets

have you soaked it in "gunk", a carb cleaner for 2 hrs ? then washed it out with a spray water hose with cool water and you can see the water flow through the passages. also when blowing out with air you can see the air come out each passage. this is the way problem carbs are cleaned. as you say you just took it apart and looked at it? gunk, water and air is the three things nessesary to clean a carb. as it sounds it has a plugged main circuit.

Did you forget to put the venture back in it?

Hold your hand over the throat of the carburetor while a helper makes an attempt to start the engine. If there's not much suction on your hand
it's an indication of low intake manifold vacuum. Also do a compression check and post the readings.

Spray some of that starter fluid in the area where your intake manifold mates to the engine block and see if the engine fires while cranking. You will need a helper. Hal

just because you can blow air thru doesent mean its realy clean enough to operate good someties you need to take small drill bits and turning

Blow air backwards up your fuel line, make sure gas cap is off, I bet you got something floating around in the fuel tank that is stopping it up. I have had a few do this, most times its a bug in there but I really wonder how they get in there