The Ford Barn

rivcokid · 10-09-2022, 09:24 AM

Hi all - I went to remove the cap jet from a Zenith carb and it broke, leaving the threaded portion in the body. Any ideas of how to get it out, given that I do not have a shop in my back yard? Or, alternately, is there someone who would be willing to give it a shot if I sent it to them, for proper remuneration of course?

Thanks

Marshall V. Daut · 10-09-2022, 09:43 AM

That jet is only brass. Carefully and slowly drill out the remains with smaller bits, leaving just a titch of the brass so that a tap can clean up the hole and re-thread it. You'll need to order a special tap from one of the Model A vendors, but it'll still be cheaper (and more personally satisfying) if you do it yourself at home instead of mailing the carb half back and forth to someone else. Besides, you can use that same tap to chase other holes in the carb that use that size and pitch tap. Include the tap in an order with other parts for your car, otherwise the shipping & handling will cost at least 2x what the tap itself costs if you order only it. Some vendors may not even complete an order that small, requiring a minimum total cost order.
Marshall

Gene F · 10-09-2022, 09:54 AM

I think you can order a tap at NAPA

katy · 10-09-2022, 10:34 AM

5M75 (metric) is the thread size.
See: https://modela.org/casting_threads.html

rivcokid · 10-09-2022, 01:30 PM

Thanks all. I'll see if I can get one. M5x.75

Chuck Sea/Tac · 10-09-2022, 05:00 PM

Sponsored Links (Register now to hide all advertisements)

Use a reverse drill

Tom Endy · 10-09-2022, 05:24 PM

Heat the area around the broken jet with a torch until the casting glows a dull red and then drop it in a bucket of cold water. The procedure will shock the brass jet loose from the casting. Insert and tap something into the jet like a small tap, or easy out and it will probably screw right out. I would avoid drilling it out.

Tom Endy

10-09-2022, 09:24 AM	#1
rivcokid Senior Member Join Date: Sep 2018 Location: Riverside, CA Posts: 174	Cap Jet Thread removal - Zenith carb Hi all - I went to remove the cap jet from a Zenith carb and it broke, leaving the threaded portion in the body. Any ideas of how to get it out, given that I do not have a shop in my back yard? Or, alternately, is there someone who would be willing to give it a shot if I sent it to them, for proper remuneration of course? Thanks

10-09-2022, 09:43 AM	#2
Marshall V. Daut Senior Member Join Date: Apr 2011 Location: Davenport, Iowa Posts: 2,113	Re: Cap Jet Thread removal - Zenith carb That jet is only brass. Carefully and slowly drill out the remains with smaller bits, leaving just a titch of the brass so that a tap can clean up the hole and re-thread it. You'll need to order a special tap from one of the Model A vendors, but it'll still be cheaper (and more personally satisfying) if you do it yourself at home instead of mailing the carb half back and forth to someone else. Besides, you can use that same tap to chase other holes in the carb that use that size and pitch tap. Include the tap in an order with other parts for your car, otherwise the shipping & handling will cost at least 2x what the tap itself costs if you order only it. Some vendors may not even complete an order that small, requiring a minimum total cost order. Marshall

10-09-2022, 09:54 AM	#3
Gene F Senior Member Join Date: Mar 2012 Location: Ohio Posts: 1,978	Re: Cap Jet Thread removal - Zenith carb I think you can order a tap at NAPA

10-09-2022, 10:34 AM	#4
katy Senior Member Join Date: Jun 2015 Location: Red Deer, Alberta Posts: 5,046	Re: Cap Jet Thread removal - Zenith carb 5M75 (metric) is the thread size. See: https://modela.org/casting_threads.html __________________ If you don't hear a rumor by 10 AM, start one!. Got my education out behind the barn!

10-09-2022, 01:30 PM	#5
rivcokid Senior Member Join Date: Sep 2018 Location: Riverside, CA Posts: 174	Re: Cap Jet Thread removal - Zenith carb Thanks all. I'll see if I can get one. M5x.75

10-09-2022, 05:00 PM	#6
Chuck Sea/Tac Senior Member Join Date: May 2010 Location: Between Seattle & Tacoma Posts: 2,354	Re: Cap Jet Thread removal - Zenith carb Sponsored Links (Register now to hide all advertisements) Use a reverse drill

10-09-2022, 05:24 PM	#7
Tom Endy Senior Member Join Date: May 2010 Location: Southern California Posts: 3,131	Re: Cap Jet Thread removal - Zenith carb Heat the area around the broken jet with a torch until the casting glows a dull red and then drop it in a bucket of cold water. The procedure will shock the brass jet loose from the casting. Insert and tap something into the jet like a small tap, or easy out and it will probably screw right out. I would avoid drilling it out. Tom Endy