Push Mower Fires- Won't Run

I have a little 20" push mower I use for trimming and has not been used much at all. From out of the box it always ran very rough.
I can press the bulb to prime it and it will run for maybe two seconds, it seems just long enough to burn the gas the priming has supplied. I cleaned the air filter and checked the spark plug. The spark plug was black with smut so I put in a new one. None of this has helped as the new spark plug has produced the same results. It seems as it is not getting any fuel as the only spark comes from the little bit of fuel that is used for priming.
Thanks in advance for any suggestions or solutions
BTW, this is a Briggs & Stratton engine.

 

It sounds like the carburetor needs to be removed and cleaned.

 

You need to install a new diaphram kit, it is Briggs part # 795083 or old # 495770 also Lowe's has a kit #5083 which has the same parts.
Here we go:

Remove air cleaner, there are 2 bolts that hold things together, one on the front of the tank 3/8" and one into the block 1/2", remove these bolts, now "slowly" slide the carb/tank off the intake tube and breather tube, now tilt the tank in to release the throttle linkage and waalaa the carb/tank is removed. Check the intake tube to see if the “O” ring seal and plastic retainer are still on the intake tube, if so remove them and re-install them into the carb. Remove the 5 screws from the carb/tank remove carb(don't loose the spring) now spray all holes, cracks and crevases in both the carb and tank surface with brake parts cleaner, remove the main screen(looks like a thimble), now with a small screwdriver pry out the main jet(carefully) and clean it, check the “O” ring on the main jet for damage, if it is damaged it must be replaced, reinstall the jet, it can be difficult some times to get it to snap back in place(I use the rounded end of a screwdriver handle). Remove and clean the fuel pickup stem(not necessary if the fuel tank was clean). Clean any junk/rust from the tank. Install the diaphram on the tank then the gasket(no goo or sealer) now carefully replace the carb(the spring will try to misalign the diaphram), tighten all screws a little at a time so as not to crimp the diaphram until they are all tight. Install the carb/tank in reverse order and you are done. If I missed something one of the real mechanics will correct me. Have a good one. Geo

 

Thanks for the replies guys. I will try to remove and clean the carb. I tried it again this afternoon even by pouring a little gas directly into the carb and it would run until it burned that gas out, less than 10 seconds. It just seems it is not getting any gas.

Grubb, I am impressed by your knowledge and this mower probably has less than 10 hours use on it so hopefully it want need all that...hopefully.

Any other thoughts would be appreciated.
Again thanks much.

 

My take is usually to try Sea Foam first. Then do the rest. A lot of times the problem isn't dirt, but rather varnish. The Sea Foam is very good at dissolving that stuff. Might try it and if if doesn't it's a small investment - $8.00 can and you have lots of it left over for other uses.

Should you go this route, add double to half a tank of gas. Prime it with the primer and don't start it, but let it sit for five minutes, Then prime again and try to start it with full choke and half throttle. Do this a couple of times and see if it doesn't loosen up for you.

Once you get it started and keep it running, fill the tank on to full with gas alone and use the mower. Add the Sea Foam to the next couple of tanks to clean it up. Then just gas for the rest of the season.

 

The kit is about $5, the labor is 30 min, you can fix it or fight it, it's not like I have only did this once. Have a good one. Geo

 

Seafoam is good stuff, but I don't recommend it for this mower. The seafoam costs more than the parts for the repair, and probably won't fix it. The diaphragm pulls out a little from under the carb between the screws on either side of the intake tube of the carb, and that's usually the cause of the problem on these.

 

It was just another thought, geo . A lot of people don't do the mechanical stuff a lot like you do and if something out of a can gets it done it's not so intimidating.

Given what Cheese has pointed out you'd have to do the mechanical fix with the cleaning and parts replacement. I just use Sea Foam to get out of work.

 

Yep, it's no problem marbobj, seafoam definitely has it's place. If it were most any other engine, I'd say go for it, but it can't put the diaphragm back into place under the carb.