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mower won't keep running


wwc's Avatar
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04-30-13, 02:56 PM   #1  
mower won't keep running

I have a push mower, 3 1/2 briggs that was put away without gas and not run for a couple years.
I squirted some starter fluid in the carb and it fires up but won't run on it's on.
the priming bulb doesn't feel like it is working and feels like no suction.
I took the carb apart and cleaned the jets and all is open and clean but still won't run on it's on.
I am thinking diaphragm, how do i change that. I didn't see anything that came apart?

 
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04-30-13, 03:37 PM   #2  
Since you didn't post the engine model numbers I will guess it has the plastic carb setting on the fuel tank:

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

 
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05-01-13, 09:19 AM   #3  
it has the gas tank on the back of the engine and the carb on the side with a hose feeding it from the tank.

I cleaned out the tank and hose and have good flow, cleaned out the hole where the jet sits and have good flow but the prime button has to vacuum from the feel of it.

where is the diaphragm on this type.

 
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05-01-13, 09:26 AM   #4  
Post your engine model info. If it's a briggs, it is stamped into the engine shroud or the metal flange over the exhaust.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
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05-03-13, 05:14 PM   #5  
craftsman eager 1

Here is the model number 917 380251

 
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05-03-13, 06:30 PM   #6  
This engine does not have a diaphram carb, it has a bowl type, the problem is usually the tiny hole in the bowl nut(main jet) being clogged, it is almost invisible. I clean it with the wire from a twist tie, check the pic below for reference. Have a good one. Geo


 
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05-03-13, 06:37 PM   #7  
I saw that and cleaned it with a very thin wire and sprayed carb cleaner thru it also, I can try again but the primer bulb didn't change pressure at all.

Is there a certain amount to turn that bolt on the bowl or just make it tight?

 
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05-03-13, 07:49 PM   #8  
That's a tecumseh engine, not a briggs. You won't feel any pressure in the primer bulb. It pushes air.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
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05-03-13, 07:55 PM   #9  
ok then since it doesn't have a diaphragm, all i need to do is clean the tiny hole better on the bowl bolt and it should feed itself ?

 
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05-03-13, 09:37 PM   #10  
If that's what is wrong, and it usually is.


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God bless!

 
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05-04-13, 08:19 AM   #11  
Also make sure the air filter mounting bracket is installed on the carb or at least the outer screw installed, the screw hole is threaded into the primer circuit. If the screw is not installed the pressure created by the primer goes out the screw hole rather than to the carb bowl and does not prime. Clean all the holes in the bowl nut not just the tiny one. Have a good one. Geo

 
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