I have an old weed eater tractor. The model is 733-848. The carburetor was acting clogged up so I took it apart. I cleaned it all out and put it back together but it is still not working. It will fire up if you pour gas right down into the carburetor so I know its got to be a fuel problem inside the carburetor. The fuel lines have been checked. The reservoir cup on the bottom of the carburetor receives fuel, but no fuel is getting sucked up into the upper part to mix with the air and enter the engine. How does this process work with this type of carburetor. Is their a single tubing that sucks gas up from the reservoir that is clogged or how does it work?

Hi,
Generally there are multple circuits used at different RPMs. The slow speed circuit works all the time, but the main jet is not fully in play until at least 3/4 throttle though it actually takes full throttle and load to use it or test it.
How about the numbers off the engine; I may know a visual source of info.
Peace,
Clarke
Just thought about it; those numbers are the Home Depot SKU; how about the real number from under the seat!

The MFG number on the tractor is HD12538. The carburetor is a Walbro 5-4993. I'm looking at it right now and I see the part that the reservoir screws up into and on each side are tubes. On is open on the end but can not blow air threw it. And the other has a ball on the end. I'm guessing the one is supposed to open and let gas up into the carb? Thanks for your help. I'm not a great mechanic.

Hi,
The best info I could find is that you have a Briggs 289707 engine. I found manuals almost of your machine; a HD13538 and WE 12538J at Free lawn and garden product owners manuals, user guides & how-to instructions | ManualsOnline
Picture of the carb and the HD13538 manual attached:
Part #142 in the drawing is the main jet and passes the fuel into the venturi of the carb for mixture with air.
Peace,
Clarke

Weedeater HD12538j hard to change gears