Briggs carb, what is this opening for?

JBtoro

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I often cut my own gaskets. When doing so on one of my B&S engines (8.75 OHV Professional Series on a Deere push mower), I had a bit of difficulty lining up & cutting the opening circled in orange on the gasket. It mates up to the hole also in orange on the carb. Then I stopped to think, what is this opening for? On a carb off of a standard 6.75, 7.0, 7,25, etc.Briggs flathead, there is also an opening on a slightly different style carb and I believe it is there to facilitate the primer pulse if the engine has a primer bulb. Well and good, but the engine on my Deere has an auto choke, not a primer. So, again, I'm wondering what this opening does? I'll bet someone here knows.

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Rivets

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Take the bowl off and spray some carb cleaner into the hole. If it comes out inside the bowl area it is a bowl vent, and/or a you stated a primer passage way. In either case I would not cover the hole with a gasket.
 

StarTech

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Is it really the trouble for a $1 gasket? And btw it is the primer and it need to be still open as it is also a fuel bowl vent.
 

ILENGINE

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That is a bowl vent that is used in combination with the primer bulb.
 

JBtoro

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Is it really the trouble for a $1 gasket? And btw it is the primer and it need to be still open as it is also a fuel bowl vent.
Thank you. Please send me a link wher
Is it really the trouble for a $1 gasket? And btw it is the primer and it need to be still open as it is also a fuel bowl vent.
Thanks. I thought it must be a vent of some sort. BTW, please send a link where I can buy the gasket for $1 including shipping.
 

JBtoro

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That is a bowl vent that is used in combination with the primer bulb.
Thanks. As I said in my original post, this mower is auto choke; ie, no primer bulb. Maybe Briggs included it just in case this carb could also be used with a primer bulb engine although the only engines I know of in this so-called "Professional" series are auto choke.
 

StarTech

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One thing you to take into account is that I am a repair shop owner. Also no where I said it included shipping.

As for me I them 20 ea at a time along with other parts so the actual is very near $1 ea plus a few cents. Matter of the last ones actually cost me 0.57 ea but that was a couple years and I still got 9 of them on hand.

But here where to find the Rotary version of the Briggs 691894 gasket. Their S&H is $6.99 regrads the size of the order so for me to just order 20 ea the price becomes $1.35 but as said I order other items which actually reduce the overall shipping cost to near the $1.

https://www.mfgsupply.com/catalogsearch/result/?q=23-13224

Today if I place them the order I sending in for these using the Oregon, my cost would $1.15 ea as the order has free shipping.
 

Born2Mow

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Doesn't matter if the carb has priming bulb or not. If fuel is to freely enter the float bowl, then air has to leave, and vice-versa.
 

JBtoro

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Okay. Good discussion; that's what I was hoping for.
 

bertsmobile1

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think the walk in retail price is about $ 2.50 AUS down here at any mower shop and every one carries them .
I charge $ 2 if you are an unknown walk in or they are part of a job.
If you are a regular customer and ask for one then it costs a "thank you" .
They cost is around 50¢ and as per Star I have to buy them in packs of 20 if bought locally but usually buy them in lots of 500 for 17¢ each from a supplier in Hong Kong
The fit is critical or they leak & the mower won't start or surges and you chance of cutting a good one by hand is less than 1 %
Making matters worse is this filter holder is highly prone to warping and leaking all by itself even is the gasket is good .
 
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