Mystery Port On Carburetor & Selecting Correct Rebuilding Kit

[PGB1]

Hello All!

On my 17 year old snow thrower, I'm having a problem with heavy exhaust smell and weak power, so I decided to rebuild/replace the carburetor, spark plug & fuel filter. Upon taking the covers off to access the carburetor & fuel filter I found the surprise described below.

On the carburetor is a port that was not connected to any tubing. It simply ended open to the air. (Photo Attached) This confused me, especially since it's in the area where snow gets sucked under the hood & gathers.

The end of the port doesn't show up in the float bowl, so it's not venting the bowl. (Photo Note: The tall, white thing to the right of the port in the photo is the shaft for the choke lever. The bolt seen behind the port isn't part of the machine. I put it there to keep the pull rope from retracting in to the winder while the handle's off.)

There are separate ports for the primer button tubing & the fuel tubing from the gasoline tank. There is no air filter on the machine & I did not find a crankcase breather, so a tube leading to/from either of those is not this mystery port.

The machine is a Craftsman snow thrower 536.8815091 (A Murray clone with the same Murray model number)
The engine is Briggs & Stratton 5BSXS-1481HE 276037.

My second mystery is finding the correct kit to rebuilt the carburetor, or even a new carburetor.
The carburetor's only numbers are 8873 & 8724. No parts sellers on line or in person know what carburetor this is.
(It's the original to the machine. I bought the machine new in 2005.)

I looked at the manual's exploded views, on line exploded views and on line parts sellers. Unfortunately they all skip the carburetor entirely, so I could not figure out what tubing goes on there. Briggs & Stratton wasn't of any help.

Do any of you know what is supposed to be attached to this tubing- if anything- And what carburetor model this is?

Thanks For Helping me solve these mysteries. I sure appreciate it.
Paul

 

[ILENGINE]

There should be some numbers stamped into the blower housing either next to the spark plug or down the side of the blower housing on the flat part next to the cylinder. In some cases it will be a tag riveted to the housing close the the flywheel on the flat part toward the spark plug.. The number that you gave the the Briggs model number is the EPA number and doesn't mean anything to anybody other than them. And most of the time the numbers on Briggs carbs are also useless.

Also may want to check the model number of the blower that you posted. Seems to have 1 too many digits.

I am really surprised that isn't a Tecumseh engine.

 

[geelee]

looks like thats where the primer bulb hose hooks up

 

[PGB1]

Thank You ILEngine & Geelee for taking time to reply with help. I very much appreciate it.
I apologize for not thanking you sooner, but life's conundrums took me away for a couple of weeks. (And, for some reason, I don't get notifications of replies to threads I'm following. Someday I'll learn computer stuff. Maybe...)

I found the stamping to which you directed me, ILEngine. It's Model 09A413 Type 02020 Code 041006YA
Having that helped me find the carburetor number. It's 669103, of which there are many variations in linkages, chokes and even flange size & hole spacing. All are obsolete & no parts are available. (I bought a close one, but there are differences. That question is in another I'm Lost! post that I made today.

As an experiment, along what you said about the primerGeelee, I tried hooking a tube to the port & blowing into it. I couldn't blow into the tube.

I took the carburetor to the local repair place. No one there knew what that mystery port was used for. Since the old carburetor's bad (broken float), for fun I'll pump water into the port, just to find where it leads. Then, maybe do an autopsy to try to find out more. (Just to learn)

You mentioned surprise that it wasn't a Tecumseh engine, ILEngine. Now that you mention it, my memory tells me all my Craftsman lawn mowers had Tecumseh engines, except the really old ones that I had in the early 70's, which were most likely from the 60's. (This is my first snow thrower. Age vs. Snow Shovel = Slow Going!)

Thanks Again to you both for helping & Please Enjoy Today!
Paul