09-21-2022, 12:43 AM | #1 |
Senior Member
Join Date: Mar 2013
Location: New Zealand
Posts: 367
|
Broken venturi
Bought a Zenith carby with a broken venturi at a swap meet. I tried unsuccessfully to drill it out, using very small drill bits at first then larger drills but it still won't come out. After using the search function here, I found that I should have used heat and I will try that next. In the meantime do you thinkI have ruined it? (see pic).
|
09-21-2022, 01:01 AM | #2 |
Junior Member
Join Date: Oct 2015
Location: Reidsville,N.C.
Posts: 10
|
Re: Broken venturi
I don't know if you ruined it but I got mine out with heat, melted out like solder. Just work safe, wear glasses, gloves and something to cover your face in case it splatters
|
Sponsored Links (Register now to hide all advertisements) |
|
09-21-2022, 01:57 AM | #3 |
Senior Member
Join Date: May 2010
Location: brentwood, ca
Posts: 4,301
|
Re: Broken venturi
pretty rough casting. The heavy corrosion along the upper edge will be a problem.
I made a Venturi extractor with threaded rod and flat washers that press out the Venturi. Haven't used heat to melt out the Venturi. You could melt the brass plugs also. |
09-21-2022, 02:25 AM | #4 |
Senior Member
Join Date: Jul 2010
Location: United Kingdom
Posts: 1,455
|
Re: Broken venturi
I agree with hotrod farm truck #2. Heat is your only hope on this one, and do take all the safety precautions mentioned... its unlikely to pop out with heat and thermal shock alone so melting it is probably the way to go
Last edited by johnbuckley; 09-21-2022 at 11:19 AM. |
09-21-2022, 08:34 AM | #5 |
Senior Member
Join Date: May 2010
Posts: 2,619
|
Re: Broken venturi
This is the safest way to remove both upper and lower halves of broken venturi.
I have removed hundreds of these with similar tool. https://www.snydersantiqueauto.com/p...9475&cat=41661 If you decide to make your own tool be very sure that the disk which goes inside broken venturi and screws on the threaded rod is the correct diameter. If disk is too large It will destroy the "shelf" in lower casting making lower casting a piece of junk. Wear a full face shield if you decide to use heat to remove. This is very dangerous I had 10 or 20 venturis Explode and spray chunks of metal around. It makes a sound like a shotgun blast and chunks go flying around. Drilling or using a hacksaw blade destroys MANY castings Many castings are damaged in various ways using drills and saw blades. Last edited by Benson; 09-21-2022 at 08:55 AM. |
09-21-2022, 09:15 AM | #6 |
Senior Member
Join Date: Jul 2010
Location: United Kingdom
Posts: 1,455
|
Re: Broken venturi
Sponsored Links (Register now to hide all advertisements)
|
09-21-2022, 09:44 AM | #7 |
Senior Member
Join Date: Dec 2014
Location: langley, wa.
Posts: 642
|
Re: Broken venturi
I have used heat, no problem, heat the casting, Venturi flows out.
|
09-21-2022, 11:52 AM | #8 |
Senior Member
Join Date: Dec 2013
Location: Waxahachie, Texas
Posts: 991
|
Re: Broken venturi
Pretty scabby looking, don't think I'd waste time trying to rebuild it unless you're looking for a challenge. As Brentwood Bob said, with the rough and corroded condition of the top mating surface, you're likely to have sealing problems. I'd trash it and find a more worthy candidate!
|
09-21-2022, 04:01 PM | #9 |
Senior Member
Join Date: Jun 2014
Location: Land of Lincoln
Posts: 3,167
|
Re: Broken venturi
I couldn’t remove screws and jets from a carb, soaked in Evaporust and the screws and jets came right out, this may help with the venturi
__________________
Don't force it with a little hammer tap, tap, tap get a bigger hammer tap done |
09-21-2022, 04:37 PM | #10 |
Senior Member
Join Date: Jul 2010
Location: Cow Hampshire
Posts: 4,188
|
Re: Broken venturi
I've done the heat and it works QUICK. Not much "solidus" in the transition from solid to liquid.
Problem for me then was the replacement venturi are "small" in diameter. Like shuck around small. Only pinching between the upper and lower halves of the carb and using the gasket worked to hold it. The carb seemed to work as normal once restored. Zenith are not my fave. Joe K
__________________
Shudda kept the horse. |
09-21-2022, 08:54 PM | #11 |
Senior Member
Join Date: Mar 2013
Location: New Zealand
Posts: 367
|
Re: Broken venturi
Thanks Guys for your helpful suggestions. The casting looks bad because it still has the old gasket attached. Will try heat next.
Mac |
09-22-2022, 03:32 PM | #12 |
Senior Member
Join Date: Mar 2013
Location: New Zealand
Posts: 367
|
Re: Broken venturi
|
09-23-2022, 11:24 AM | #13 |
Senior Member
Join Date: May 2010
Posts: 2,619
|
Re: Broken venturi
|
09-23-2022, 03:55 PM | #14 |
Senior Member
Join Date: Mar 2013
Location: New Zealand
Posts: 367
|
Re: Broken venturi
Thanks, I might try that first.
|
09-24-2022, 08:22 AM | #15 |
Senior Member
Join Date: Aug 2017
Location: SoCal Desert
Posts: 826
|
Re: Broken venturi
Are the GAV threads still viable?
Regards Bill |
09-29-2022, 09:05 PM | #16 |
Senior Member
Join Date: Mar 2013
Location: New Zealand
Posts: 367
|
Re: Broken venturi
Just to round off this thread: In the end I decided to make a pulling tool. This was a 1.175-inch "plug" that I pressed through with a hydraulic press. Once the plug was made on the lathe, the rest was very quick and easy.
Mac |
09-30-2022, 08:31 AM | #17 |
Senior Member
Join Date: May 2010
Posts: 2,619
|
Re: Broken venturi
It should be noted that with the lower casting the venturi needs to come out from the top of the casting.
If venturi is pressed down into the casting, the shelf inside the casting will be broken off. |
09-30-2022, 09:54 AM | #18 |
Senior Member
Join Date: Jun 2015
Location: Red Deer, Alberta
Posts: 5,093
|
Re: Broken venturi
He probably went through the main jet opening to press the venturi out.
__________________
If you don't hear a rumor by 10 AM, start one!. Got my education out behind the barn! Last edited by katy; 09-30-2022 at 09:54 AM. Reason: Correction |
09-30-2022, 03:56 PM | #19 |
Senior Member
Join Date: Mar 2013
Location: New Zealand
Posts: 367
|
Re: Broken venturi
Sorry, I should have explained: I decided to use a different lower casing without a stuck venturi, so I was pressing the broken venturi only out of the top casing. It is of course impossible to press a broken venturi out of the bottom casing - only a puller (or melting) could achieve that.
|
|
|
Sponsored Links (Register now to hide all advertisements) |
|