Lawn mower starts then dies

Hi everyone... First off, I just want to say that I am not savvy when it comes to this stuff but I need some help. I have a Yard Machines Push-Mower (158cc I believe) that I bought from Home Depot about a year ago. I have used it several times and always had trouble starting it, but I always eventually got it to start and stay on. Now, it won't start at all. I push the prime button, pull the cord, then it dies in about less than five seconds. The only way it will actually stay running is if I constantly push the prime button while it is running (which is impossible to do in order to push the mower). I went to Home Depot, they told me that I possibly needed a new filter but I told them that the mower is practically brand new. So, they told me to clean the filter by soaking it in gas, squeezing out the gas and then let it air dry... so I did. I also put new gas in the mower, and took apart the carb. The carb was perfectly clean considering I used the mower only a handfull of times. I have no idea what else to do or how to get it started. I can't return/exchange it because it is past their 30 day policy.

 

I am guessing this mower has a Briggs engine with the carb setting on top of the fuel tank. If so;
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 a lot geo... I just checked Lowes and it looks like the diaphragm kit is about $3.00. I am going to call them tomorrow to make sure they have it and will change it. Sounds like you knew right away that it has a Briggs engine and knew what the problem most likely is... What is wrong with the diaphragm that came with the mower?

 

The diaphrams get stiff over time and will no longer work properly, although the mower is only a couple years old, you never now how old the diaphram is, the carb may have set on the shelf for several years before being installed on an engine. I pulled 4 brand new Poulan/Weedeater mowers out of the trash a walmart all had the same diaphram problem. Have a good one. Geo

 

Are you sure the mower has a Briggs engine? And not an MTD engine? Are you sure it is a diaphragm carburetor and not a bowl type? To be sure, find and post back with your chassis and engine ID numbers.

 

Hi everyone... First off, I just want to say that I am not savvy when it comes to this stuff but I need some help. I have a Yard Machines

 

Does it have a separate choke, or is it integrated with the throttle. Once an engine starts, and runs for a few seconds,

 

We'd have to know more about the 158cc engine. There are a lot of 160s out there of many types. Typically this problem is from the engine running out of gas. If it has a float bowl (fuel bowl) on the carburetor you may find some some metering orifices in the center bolt that holds it on the carb. On some engines there are some tiny bleeds there that clog easily. You stand the mower up on it's wheels with the carb side up and remove that bottom bolt. Look at it carefully to see if there is a very small hole in the bolt that might look like a speck of dirt. Clean the bolt, and if it has the small bleed, rod it out with the soft steel wire out of a wire tie, like on a loaf of bread.
BTW, any air filter that you clean by washing is supposed to be oiled before using. You put some engine oil on it, work the filter to distribute it and wrap it up in some paper towels and squeeze out the excess.