Dave u are on the right track, if u pour fuel in the carb,and it runs till it burns the gas that was poured in. You still have a blockage in that carb, I am not sure what engine u have but if its the pulsa prime carb with the tank below the carb, u would need a diaphram set.And every piece of that carb taken apart and cleaned, also that mainjet can be pried out with a small screwdriver, carefully.also the primmer bulb should be pulled off and replaced and the small seat and ball and spring, removed and carbcleaner and air shot threw that passageway, Also make sure u can blow air threw the fuel pickup pipe. Hope this helps

Usually replacing the diaphragm will fix the problem. Use compressed air carefully for the other parts.

Thanks for the good information. I am going to get a carburetor rebuilding kit and also replace the primer bulb and follow your instructions. The engine is a B&S GOLD 6hp easy start quiet. The carburetor mounts on the side of the engine with the primer bulb facing the front. Thanks again dave

The 6 horsepower engine is most probably the 12 cubic inch Quantum series - not the smaller engine with the diaphram carburetor.

Since you have already disassembled and cleaned the carburetor, try starting the engine with 5 - 6 drops of gasoline poured directly in the venturi area of the carburetor. If the engine fires up - then dies, changes are the problem is still in the carburetor. The main fuel jet is located in the bolt that holds the float bowl to the carburetor. This must be cleaned with spray carburetor cleaner. Other solvents are not effective. There is no problem running this engine with the air filter removed - just don't mow your yard until the filter is installed.

If the engine starts - and continues to run, inspect your primer system. Install a new gasket between the plastic filter base and the carburetor. Do not install the filter or filter cover. Use a flashlight and observe the venturi area of the carburetor while depressing the primer bulb. You should see some fuel discharging. If there is no fuel, please ask for additional information.

I bought the carburetor rebuilding kit as it came with several gaskets, needle but was missing the seat. I'm going to go back tomorrow and get the seat. I don't trust putting the old one back in. I also replaced the primer bulb with a new one. All the openings in the carburetor seem to be open and not blocked. I suspect it is the bolt (main jet) that is blocked as was mentioned above. I should get the mower running tomorrow. I will keep you posted. Thanks again for everyones help. dave

Got the engine running after taking extra attention to cleaning the main jet bolt and changed the needle & seat. The center hole in the main jet bolt seemed to be blocked. It started on the first pull. However now I have another problem. I ran the engine about 30 minutes yesterday then shut it off. Even a half hour later no leaks. This morning the gas leaked out of the carburetor. I am certain it is in the area of that seat. I have the new seat in correctly with the molded ridges facing the bottom. Maybe I didn't press it firmly enough or is it possible I damaged the area when I removed the seat. I used a small ice pick tool and tried to remove it carefully.

Today I removed the carburetor and pressed in the seat a little firmer. I ran the engine for about 30 minutes and shut it off. After 2 hours no leaks. I'll check for leaks tomorrow. If it leaks I'll install another needle and seat. Any more suggections. I appreciate everyones help. dave

Often when you remove the fuel line, you'll break loose a bit of crud. If you don't flush the line, the crud flows right back to the needle/seat, causing it to leak.

Thats something I haven't thought of. How about I replace that old gas line hose. I have extra gas hose on hand. I only need about 8" or so. Should I add a gas filter. Thanks dave

yes it would be a good idea to add a standard Briggs and Stratton fuel filter to the new line. Sometimes the valve seats go bad if they sit in the shop for too long.

I'll replace the gas line tomorrow and add a new fuel filter. If it's not leaking from tonight through tomorrow like say noon should I just leave the seat alone and just do the fuel line and gas filter or should I replace the seat to be sure. I appreciate the good help. dave

And don't forget to add a fuel shut-off to your
line.

Fuel shut off, that's a good idea. I just checked my mower this morning and it's not leaking. I'll do the fuel line and shut off today. I appreciate the good help. dave

Lawnmower fixed. Installed new gas hose, shut off, and fuel filter. The mower starts on the first or second pull, and no more gas leaks. This forum was a great help. Thanks again dave