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Delco Light 4-B-12 Carb Help

44dwarf

Registered
Hello All.
I picked up an old but in really nice shape Delco light 4-B-12 unit. I check the oil it was at a good level, points were toast and had been converted by someone to Ford tractor points so i replaced with same from good old TS. Got it to run well dripping fuel into the carb while fiddling with the needle no luck getting it to run on the fuel in the tank so i put it a side a week had some time pulled out the carb from the tank the whole lower unit is rotted off. I've got it all cleaned up in the ultrasonic cleaner but lack what its supposed to look like when whole. Anyone got pictures for a 4b12 carb out of the gas tank?

---------- Post added at 06:09:23 PM ---------- Previous post was at 05:58:04 PM ----------


Hope this public link to my facebook pictures works

---------- Post added at 06:14:53 PM ---------- Previous post was at 06:09:23 PM ----------

https://www.facebook.com/media/set/?set=a.1723047657801654&type=1&l=c55d99051b
 

Mike Schweikert

Subscriber
Age
54
Last Subscription Date
07/09/2019
Re: Delco light 4-B-12 Carb help.

I have the 4B3, which is the 32 volt version of yours. 4 is 400 watts B is battery charging and 3 is 32 volts.

Here is what I believe would be the same can you have inside the tank, this one is going in mine as well.....

It uses a float inside the brass can. Delco Don (RIP) once told me how it works and those emails are long deleted by a stupid server problem years ago,.

I think it lets in a small amount of fuel to be vaporized as it gets into the carb body that sits on top of it and the float inside only allows a small amount to get in the can. You can see clearly the pick up tube and the vent, plus the small hole in the bottom to allow the can to fill some with gas.

I don't know anything else about its function. My 4B3 was missing the intake tube as well as the carb on top. Don had one and sold it to me before he passed away.

I might guess that a briggs and Stratton brass pickup tube with a brass check ball end could be grafted on to what you have left. Looks about the same size


Hope it helps...

Mike
 

Attachments

44dwarf

Registered
Re: Delco light 4-B-12 Carb help.

Thank you, Mike.

Yes I believe your correct the can should be sealed with only the needle valve opening that would allow a very low fuel height, with an unchanging vapor pressure due to tank level changing. I wonder if this is one of the ways they got them to run on both kerosene or gas or so i've read but theres not alot out there. I'll try to spin up a brass cup and repair mine but it might not be to quick so many projects....

Tony
 

44dwarf

Registered
Re: Delco light 4-B-12 Carb help.

Mike.
Did yours have a paper gasket or an o-ring on the top to seal the fuel tube to the venturi?
The last owner used red silicone.... errrr hate that stuff.
 

Mike Schweikert

Subscriber
Age
54
Last Subscription Date
07/09/2019
Re: Delco light 4-B-12 Carb help.

I cut up a paper gasket for mine with some ultra black to seal it:wave:
 

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