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MTD push mower fires but won't stay running


sthomas77's Avatar
Member

Join Date: Nov 2008
Posts: 20
NY

08-07-11, 06:50 PM   #1  
MTD push mower fires but won't stay running

Like the title says, I have a MTD yard machine mower with a B&S 4.5 engine that won't stay running. I can get it to fire and run for about 5 seconds by spraying starting fluid in, but thats it. Even continuous sprayings don't help. Gas is about a month or so old. It has run fine all season until now. The model and serial number are:
10a902 2190 b1 02120655
Any help is appreciated, thanks!

 
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geogrubb's Avatar
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Join Date: Jun 2006
Posts: 2,333
MO

08-07-11, 06:55 PM   #2  
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

 
sthomas77's Avatar
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Join Date: Nov 2008
Posts: 20
NY

08-12-11, 10:29 AM   #3  
Ok, so im an idiot. I started to drain the tank so I could replace the gaskets and I notice a separation in the liquid. Turns out the tank was half full of water. I had left the mower out for a night and it must have rained and I didn't realize it. Drained the tank and refilled and it runs again. I will keep the kit and replace the gaskets anyway with my fall service. Thanks for your help!

 
geogrubb's Avatar
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Join Date: Jun 2006
Posts: 2,333
MO

08-12-11, 02:54 PM   #4  
I have run into a lot of water in the gas problems this summer, maybe the distributors are pumping their tanks dry trying to wait as long as possible in hopes the price goes down before they must refill or something. Have a good one. Geo

 
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