venturi removal tool

[sphooch]

Hi Guys, need some help here. I'm trying to understand HOW THE VENTURI REMOVAL TOOL ACTUALLY WORKS. I HAVE THE CARBURETOR REBUILD BOOK BY Paul Moller WERE HE SHOWS HOW TO MAKE ONE BUT FAILS TO EXPLAIN HOW TO USE IT. I've searched this site with no success. any help will be greatly appreciated thanks THE HOOCH

[Jim/GA]

Look at this:
https://www.model-a.org/venturi_extraction.html

[Anteek29]

My Zenith has a very loose venturi...could this be the reason why I cannot get my A to idle properly? Should the venturi fit snugly in the body?

[BillCNC]

They can be made with a piece of all-thread, a couple of nuts, washers and a rubber plug.

Double nut the bottom> washer > rubber plug> washer > and the last nut.

Put the plug into the venturi, tighten the top nut until the rubber plug expands inside the venturi and tightens up gripping the venturi and simply pull it out. If it's stuck in real good, you will need to use a penetrating oil FIRST regardless of which method is used to remove the venturi.

The rubber plug method is really the only one to safely remove them without the fear of damaging it an any way, unless they simply fall out like one of my (3) Zeniths-1 did.

Regards
Bill

[johnbuckley]

Originally Posted by Anteek29

My Zenith has a very loose venturi...could this be the reason why I cannot get my A to idle properly? Should the venturi fit snugly in the body?

It should be a snug fit from an engineering and theoretical point of view ..... But a loose venturi is usually no problem ( unless it's loose even when upper and lower halves are bolted up together ) since the main gasket between the upper and lower bodies seals it. The Venturi has next to no effect on idling..... it's presence is to increase the airspeed as it passes across the openings of the main and cap jets ( which aren't deployed at idling) . You can even take Venturi out completely and the car will normally idle just the same.
Removal.... they can be an absolute B*****, , they can be seized into the U and L body castings. splitting when you separate the bodies . it's then you often find that someone has previously mangled them trying to effect removal, Try penetrating oil, puller, gentle tapping of central section of puller with hammer, heat and more tapping ditto , thermal shock ( in that order) .... and I had one today that someone had so severerly b*ggered in the throat of the lower body that I had to melt it out with an acteylene/propane torch.

[Joe K]

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I did the melt removal of my seized (and later mangled by me in attempt) with an acetylene torch - and found that the repop venturi fit loose - but as said, the gasket "centers" it and the two body halves "clamp" it in place.

Not my favorite carb - but works well as a spare below the seat.

Joe K

[1crosscut]

Originally Posted by Anteek29

My Zenith has a very loose venturi...could this be the reason why I cannot get my A to idle properly? Should the venturi fit snugly in the body?

Grab the shaft on your butterfly valve and see if there is movement where it passes through the side wall of the carburetor. If worn it can pull too much air in through there causing idle problems.

[Tom Wesenberg]

I had to torch a couple venturi out, but be sure to wear a full face shield, because that pot metal likes to splatter when heated.

[ursus]

I am surprised that nobody has yet mentioned an old and effective trick for removing a stuck venturi!! Place the assembly in oven at 400 degrees Fahrenheit for 10 minutes. Remove assembly and place in paper bag and place this in the freezer for another 10 minutes. Remove the bag and tap softly on a piece of wood and the venturi will fall out. Works for me.

[BillCNC]

I would think 400° would cause the paper bag to ignite and or melt the inside of your freezer.

YES, ... that kind of expansion and contraction would certainly do the trick without the use of penetrating oil.

Regards
Bill