carb question

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Jan 15, 2005 | 11:55 PM

dcotton

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From: Tucson,AZ

carb question

I just bought a 68 f100 and rebuilt the motorcraft 2v carb. I have a Motor manual that covers '62 to '75 trucks, (what a Godsend over the years). Some good pics and instructions on the carb, and I have messed around with alot of old fords, but have never seen this before.
On the accelerator pump there (was) a bracket with a spring, arm, and rubber seal mounted that when then in idle position the seal is lifted off of the fuel bowl vent. While accelerating the seal closes off the vent.
The motor manual and carb kit say nothing about this. I am really curious about this and it's purpose.
F.Y.I. I sealed the opening and removed the arm, but am curious what it is supposed to do. My big concern was when the truck was turned off and sitting, the vent is open allowing crap to enter the vent.
Just wondering, D

Jan 16, 2005 | 01:34 AM

ford390gashog

Fleet Owner

Joined: Jan 2004

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From: Brentwood,CA

that is the purge vent it should be connected to the vacuum line off the charcoal canister to suck the fumes back in

Jan 16, 2005 | 10:20 AM

dcotton

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From: Tucson,AZ

question with picture

Here is a pic to show what I'm talking about. There is nowhere to connect a vacume line, and my truck doesn't have a vapor canister.
Thanks, Dennis

There is a bigger pic in my gallery. (#6)

Jan 16, 2005 | 02:24 PM

LxMan1

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From: Louisville,Ky.

It wents the fuel vapors into the aircleaner assembly and they get sucked down the carb and burned so that they don't exit into the air.

Jan 22, 2005 | 02:53 AM

jfinlen

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Doesn't sound like the original carb. I don't remember seeing anything like that on trucks till 79. CA models might have been earlier though. Cars are a whole other story.