The Ford Barn

fixitphil · 03-02-2018, 03:30 PM

Does anyone know where I can find the article "The Zenith Carburetor"?

Hoogah · 03-02-2018, 04:00 PM

This is Tom Endy's (2010) article by that name:
http://modelabasics.com/Carb/ZenithPassageways.pdf

johnbuckley · 03-02-2018, 04:01 PM

any more clues... author? .... magazine?...... club?...... web based?

chap52 · 03-03-2018, 08:06 AM

Here is a handy troubleshooting chart I picked up from somewhere.

Anteek29 · 03-03-2018, 09:55 AM

Thanks to Hoogah and Chap52 for sharing!

TJMack · 03-06-2018, 09:00 AM

Sponsored Links (Register now to hide all advertisements)

Here's a link to an exceptional collection of information on anything related to the Zenith carburetor. I wish I had found it before trying to learn a lot of it the hard way.

Look around the website. There are numerous categories to help, with clickable links within them that share good tips.

Armed with this and Tom Endy's excellent article you should be able to handle most issues with the carb.

http://www.model-a.org/default.html

BillCNC · 03-06-2018, 12:51 PM

Looking at the link TJMack has provided, I saw this in regards to shutting down an "A".

https://www.model-a.org/shut_down.html

1. Engage emergency brake by pulling back on it.

2. Push Left Lever (Spark Control) all the way up (retard position)

3. Push Right Lever (Throttle) all the way up

4. Turn Gas Valve under dash on passenger side to closed position (pointing to the Left).
If vehicle is going to be left over night, or similar circumstances, it's a good idea to let the engine burn up the majority of the gasoline in the carburetor by letting engine run until it stalls.

6. Turn Off the Lights and any other Accessory

7. Turn Ignition Switch off (Counter Clockwise)

#4, ... I unserstand the turning off of the gas valve, but why would you want to run it out of gas if your going to drive her again the next day or in a couple of day's? A week or more of sitting I understand, ... but the way they put it, I see no reason what so ever to follow #4. ALSO running an engine out of fuel tends to be something you don't want to do.

Is there something I'm missing here?

Regards
Bill

Tom Wesenberg · 03-06-2018, 12:58 PM

Bill, it looks like they are assuming the tank valve leaks. If it leaks, then it needs to be repaired. The first winter I owned my 29 Tudor, the tank valve and carb needle and seat both has small leaks, and I lost a full tank of gas. I lapped both valves with toothpaste and haven't leaked a drop in the past 20 years.

BillCNC · 03-06-2018, 01:16 PM

Hi Tom,

I get that part, ... but draining the carb or running out of fuel is only something you do for storage to prevent lacquer build up from gas degradation.

What advantage does this have on a daily basis other than running your car extremely lean, something we need to avoid.

Regards
Bill

TinCup · 03-06-2018, 01:21 PM

Don't forget this great write up and animations on the Zenith carb.
Zenith Carb Basics

Tom Wesenberg · 03-06-2018, 01:27 PM

Quote:

Originally Posted by BillCNC

Hi Tom,

I get that part, ... but draining the carb or running out of fuel is only something you do for storage to prevent lacquer build up from gas degradation.

What advantage does this have on a daily basis other than running your car extremely lean, something we need to avoid.

Regards
Bill

If the tank and carb valves leak just a tiny bit, the carb bowl can fill during the night, and might not overflow and leave gas flowing out the carb to drip on the floor.

BillCNC · 03-06-2018, 01:54 PM

Like I said, I get the gas shut off, and if it is shut off, no gas will get to the carb if the valve works correctly. If it doesn't draining the bowl or running the carb out of gas is pointless it will just fill up again throughout the night.

On the other-hand, if you have a perfectly functioning gas valve, ... there is no point in running it out of fuel or draining the bowl. it's a waste of time, gas, wear and tear on the carb drain plug and leaves a door open to the possibility of issues due to running it lean every night.

Regards
Bill

California Travieso · 03-06-2018, 06:15 PM

Quote:

Originally Posted by BillCNC

Like I said, I get the gas shut off, and if it is shut off, no gas will get to the carb if the valve works correctly. If it doesn't draining the bowl or running the carb out of gas is pointless it will just fill up again throughout the night.

On the other-hand, if you have a perfectly functioning gas valve, ... there is no point in running it out of fuel or draining the bowl. it's a waste of time, gas, wear and tear on the carb drain plug and leaves a door open to the possibility of issues due to running it lean every night.

Regards
Bill

I haven't noticed any leaks in my carb, but my experience is that if I park the car in an enclosed garage I can definitely smell gas the next morning, and my wife lets me know about it.

If I let the carb run dry, I don't get the gas smell so I think that validates that 1) I don't have a leak in the valve or the carb, and 2) the gas is evaporating from the carb.

David Serrano

Dutie · 03-06-2018, 08:28 PM

Tom and Bill both have good concerns. My experience with a possible gas leak on the garage floor is a nightmare especially with the gas hot water heater and garage heater pilot lights with my wife and I sleeping upstairs.

The valve shutoff on my roadster is on the outside raised firewall and I believe it the same one Tom is referring to that he laps with toothpaste. I also believe these valves work great when lapped correctly...however the gravity fed carb can have lots of issues as have been discussed here. The one issue that comes to me and is just my opinion is that little bit of gravity is just enough to test some valves and seats when there not just perfect. My fix was a POSITIVE in line shut off valve from Brattons for about 50 bucks. Connects to the bottom of the firewall valve and the other end directly to carb. Shuts the gas off COMPLETELY....no guessing. So please fellas don't mess with a valve that may leak, to scary for me.

Dutie

Tom Wesenberg · 03-06-2018, 08:59 PM

Heat soak can be a problem. Today's crap gas, and even the better gas without corn, evaporates and boils too easily compared to the good gas of the 60's. During a hot shut down the carb absorbs engine heat and the gas in the carb boils, so running it low helps to not get gas boiling over and out the carb throat.

Brentwood Bob · 03-06-2018, 10:19 PM

A speck of rust is all it takes to cause a problem. The run it dry takes a minute, why not do it. Your life or property damage is enough reason for me. After loosing half a tank by not doing it I learned my lesson.

TJMack · 03-07-2018, 08:36 AM

TinCup, thanks for posting that link. That animation is fantastic. So are Tom Endy's two articles. I've saved them all for future reference.

03-02-2018, 03:30 PM	#1
fixitphil Member Join Date: Mar 2017 Posts: 83	The Zenith Carburetor Does anyone know where I can find the article "The Zenith Carburetor"? __________________ FixitPhil

03-02-2018, 04:00 PM	#2
Hoogah Senior Member Join Date: Feb 2014 Location: Warrnambool, Victoria, Australia Posts: 800	Re: The Zenith Carburetor This is Tom Endy's (2010) article by that name: http://modelabasics.com/Carb/ZenithPassageways.pdf

03-02-2018, 04:01 PM	#3
johnbuckley Senior Member Join Date: Jul 2010 Location: United Kingdom Posts: 1,441	Re: The Zenith Carburetor any more clues... author? .... magazine?...... club?...... web based?

03-03-2018, 09:55 AM	#5
Anteek29 Senior Member Join Date: Dec 2014 Location: Santa Maria, CA Posts: 985	Re: The Zenith Carburetor Thanks to Hoogah and Chap52 for sharing! __________________ Alan 1929 Special Coupe 1941 Pick-Up 1955 Victoria

03-06-2018, 09:00 AM	#6
TJMack Member Join Date: Mar 2017 Location: Venice, Fl and Marcy, NY Posts: 93	Re: The Zenith Carburetor Sponsored Links (Register now to hide all advertisements) Here's a link to an exceptional collection of information on anything related to the Zenith carburetor. I wish I had found it before trying to learn a lot of it the hard way. Look around the website. There are numerous categories to help, with clickable links within them that share good tips. Armed with this and Tom Endy's excellent article you should be able to handle most issues with the carb. http://www.model-a.org/default.html

03-06-2018, 12:51 PM	#7
BillCNC Senior Member Join Date: Aug 2017 Location: SoCal Desert Posts: 826	Re: The Zenith Carburetor Looking at the link TJMack has provided, I saw this in regards to shutting down an "A". https://www.model-a.org/shut_down.html 1. Engage emergency brake by pulling back on it. 2. Push Left Lever (Spark Control) all the way up (retard position) 3. Push Right Lever (Throttle) all the way up 4. Turn Gas Valve under dash on passenger side to closed position (pointing to the Left). If vehicle is going to be left over night, or similar circumstances, it's a good idea to let the engine burn up the majority of the gasoline in the carburetor by letting engine run until it stalls. 6. Turn Off the Lights and any other Accessory 7. Turn Ignition Switch off (Counter Clockwise) #4, ... I unserstand the turning off of the gas valve, but why would you want to run it out of gas if your going to drive her again the next day or in a couple of day's? A week or more of sitting I understand, ... but the way they put it, I see no reason what so ever to follow #4. ALSO running an engine out of fuel tends to be something you don't want to do. Is there something I'm missing here? Regards Bill

03-06-2018, 12:58 PM	#8
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: The Zenith Carburetor Bill, it looks like they are assuming the tank valve leaks. If it leaks, then it needs to be repaired. The first winter I owned my 29 Tudor, the tank valve and carb needle and seat both has small leaks, and I lost a full tank of gas. I lapped both valves with toothpaste and haven't leaked a drop in the past 20 years.

03-06-2018, 01:16 PM	#9
BillCNC Senior Member Join Date: Aug 2017 Location: SoCal Desert Posts: 826	Re: The Zenith Carburetor Hi Tom, I get that part, ... but draining the carb or running out of fuel is only something you do for storage to prevent lacquer build up from gas degradation. What advantage does this have on a daily basis other than running your car extremely lean, something we need to avoid. Regards Bill

03-06-2018, 01:21 PM	#10
TinCup Senior Member Join Date: May 2010 Location: OKC / Tonkawa, Ok. Posts: 1,977	Re: The Zenith Carburetor Don't forget this great write up and animations on the Zenith carb. Zenith Carb Basics __________________ Oklahoma City Model A Restorers Group.

03-06-2018, 01:54 PM	#12
BillCNC Senior Member Join Date: Aug 2017 Location: SoCal Desert Posts: 826	Re: The Zenith Carburetor Like I said, I get the gas shut off, and if it is shut off, no gas will get to the carb if the valve works correctly. If it doesn't draining the bowl or running the carb out of gas is pointless it will just fill up again throughout the night. On the other-hand, if you have a perfectly functioning gas valve, ... there is no point in running it out of fuel or draining the bowl. it's a waste of time, gas, wear and tear on the carb drain plug and leaves a door open to the possibility of issues due to running it lean every night. Regards Bill

03-06-2018, 08:28 PM	#14
Dutie Senior Member Join Date: Sep 2016 Location: Kingston N>Y> Posts: 121	Re: The Zenith Carburetor Tom and Bill both have good concerns. My experience with a possible gas leak on the garage floor is a nightmare especially with the gas hot water heater and garage heater pilot lights with my wife and I sleeping upstairs. The valve shutoff on my roadster is on the outside raised firewall and I believe it the same one Tom is referring to that he laps with toothpaste. I also believe these valves work great when lapped correctly...however the gravity fed carb can have lots of issues as have been discussed here. The one issue that comes to me and is just my opinion is that little bit of gravity is just enough to test some valves and seats when there not just perfect. My fix was a POSITIVE in line shut off valve from Brattons for about 50 bucks. Connects to the bottom of the firewall valve and the other end directly to carb. Shuts the gas off COMPLETELY....no guessing. So please fellas don't mess with a valve that may leak, to scary for me. Dutie

03-06-2018, 08:59 PM	#15
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: The Zenith Carburetor Heat soak can be a problem. Today's crap gas, and even the better gas without corn, evaporates and boils too easily compared to the good gas of the 60's. During a hot shut down the carb absorbs engine heat and the gas in the carb boils, so running it low helps to not get gas boiling over and out the carb throat.

03-06-2018, 10:19 PM	#16
Brentwood Bob Senior Member Join Date: May 2010 Location: brentwood, ca Posts: 4,234	Re: The Zenith Carburetor A speck of rust is all it takes to cause a problem. The run it dry takes a minute, why not do it. Your life or property damage is enough reason for me. After loosing half a tank by not doing it I learned my lesson.

03-07-2018, 08:36 AM	#17
TJMack Member Join Date: Mar 2017 Location: Venice, Fl and Marcy, NY Posts: 93	Re: The Zenith Carburetor TinCup, thanks for posting that link. That animation is fantastic. So are Tom Endy's two articles. I've saved them all for future reference.