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B&S / Craftsman Lawn Mower - Priming question


WyrTwister's Avatar
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06-13-14, 03:43 AM   #1  
B&S / Craftsman Lawn Mower - Priming question

The little red primer bulb is on the side of the plastic piece that is attached to the carburetor . That piece holds the rectangular air filter . A second plastic piece attaches & clamps the air filter in place .

I have to manually prime the lawn mower through the carb or spark plug hole .

I have installed the red rubber bulb & a replacement carb . No joy . Is there a little " ball bearing " for a check valve , that I may / probably lost ?

My understanding is the red rubber bulb forces sit into the carb bowl , pressurizing it . And this forces gas into the air path of the carb , priming it ?

This is not happening on mine .

Thanks ,
Wyr
God bless

 
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06-13-14, 07:39 AM   #2  
What is the model, type & code numbers!!

 
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06-14-14, 02:31 AM   #3  
Will look up all the numbers , I can find on it , today .

Thanks , :-)
Wyr
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06-14-14, 05:58 AM   #4  
Hello WyrTwister,

Over time these plastic air filter bases warp, That leads to a gasket air leak at the carb causing the carb not to pressurize.

The fix is replace the air filter base or repair as I do, Stack two or three gaskets between the filter base and carb but don't over tighten. Also, Make sure to use the exact gasket for your engine model number as there are a couple different ones that look nearly the same.....


Good Luck

 
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06-14-14, 08:48 AM   #5  
How many times do you push the primer bulb?

I have a smaller Briggs (155cc) on my edger but it also has the red primer bulb. Even though the book says to "prime 3 times" I've found you'll pull your arm out of its socket before it starts.

I prime it 10 times and it usually starts on one pull, been that way for six years when I bought it new.

Not sure if there is something wrong but that's the way it is.

 
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06-14-14, 02:23 PM   #6  
When it was new , 3 pushes on the priming bulb would do it . Over the years 10 - 15 were needed . Now , it quit working all together & have to use gas or starting fluid in the carb or spark plug hole . :-(

Tried a new gasket ( only had one on hand ) . No difference . :-(

No one open that would have the parts I need , this afternoon . Will buy 3 gaskets next week .

With the starting fluid , I got it started & mowed the front , before I tuckered out & got too hot .

CraftsMan Lawn Mower Photo by WyrTwister | Photobucket

Thanks ,
Wyr
God bless

 
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06-14-14, 02:37 PM   #7  
Hello Baldwin,


If you have been pushing that primer 10 times since new, There was something wrong when you purchased it. No new machine should require that many pumps.

If you have the same square plastic base as WyrTwister, You may want to try a couple more gaskets as well. If your's is different, Post your engine model and type/spec numbers so I can take a look.


WyrTwister,

I'm pretty confident doing this will solve your issue.

Good Luck

 
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06-15-14, 03:59 AM   #8  
Thanks , :-)
Wyr
God bless
Happy Fathers Day

 
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06-15-14, 10:01 AM   #9  
Numbers are: 10T502/0457B1 if I'm using the right book. I can take a picture when I go out.

Is this what you are talking about....





Thanks

 
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06-15-14, 11:01 AM   #10  
Or this one:







 
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06-15-14, 11:52 AM   #11  
Hello Baldwin,


Neither of those two gaskets, Your engine has a different carb and air filter than WyrTwister's.

Inside your carb is a primer check valve which appears to not be functioning properly, It's shown as #11 in this illustration; Disassembly, Cleaning and Repair of Briggs and Stratton Tank-mounted Pulsa-Prime Carburetor

You can try cleaning and see if that helps or you can replace the assembly with part #494409, You could also just replace the whole carb part #795477 that comes with a new diaphragm-pump spring-screen and air filter gasket then be done with it. Their listed on Ebay for $22.99 with free shipping, Your running on borrowed time right now with your diaphragm having to run today's ethanol fuel.

On this carb with the primer working properly, It WILL flood the engine if pumped 10 times.


Good Luck

 
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06-15-14, 12:14 PM   #12  
I think the first picture does look like what I have, I'll have to go out and look.

Thank you very much!!

 
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06-15-14, 01:01 PM   #13  
Hello Baldwin,

You are correct in that your engine uses both the gaskets you posted, But.... Replacing either will not solve your primer issue. Revert back to my previous post to address your primer bulb issue.


Good Luck

 
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06-16-14, 04:01 PM   #14  
I bought 2 more gaskets this PM , after work . Install them with the 1 that was already on it ( total of 3 ) . Seems to be working as it should ! :-)

Praise the Lord! :-)
Wyr
God bless

 
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06-16-14, 07:32 PM   #15  
Hello WyrTwister,


Thanks for the update, Glad it worked out for you !

31

 
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06-17-14, 02:08 AM   #16  
Thanks all , for the help . I was about to give up on the old thing .

Wyr
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06-22-14, 10:03 AM   #17  
Both the Craftsman mower and the Poulan Pro Lawn Mower ( that my boss gave me & have been using as a " parts donor " ) are running . Thanks to the advice to use 2 gaskets between the back air cleaner housing / priming assembly . :-)

I have to prime it about 10 pushes of the red rubber bulb , when cold . But that is much better than not at all .

The Poulan Pro Lawn Mower , I dumbed up and stripped one of the 2 screws holding the air cleaner assembly to the carb . :-(

I drilled it out & tapped it 1/4" x 20 tpi . Used a 1/4" x 20 x 3/4" screw & seems to work OK .

Thanks all , :-)
Wyr
God bless

 
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