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Carter BBS bowl vent
https://slantsix.org/forum/viewtopic.php?t=50091
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Author:  64ragtop [ Mon Oct 15, 2012 6:17 pm ]
Post subject:  Carter BBS bowl vent

The Factory Service Manual goes into some detail about setting the accelerator pump by adjusting the Pump operating rod by bending it. My pump operating lever raises the pump as it should, then I'm supposed to measure how far the bowl vent has opened. The bowl vent does not open. The manual says "note that the hairpin clip (which opens the bowl vent) can be placed....."

Well, maybe so - if you have said clip! So, how important IS the opening of the bowl vent anyway?? Seems to me that it would be a great place for fuel to evaporate from. But, if the bowl vent doesn't open then the accelerator pump setting can't be checked.

I dunno, likely I'm making a mountain out of a molehill. If so, someone please give me a (literal) swift kick in the pants to help me reset my priorities.

ATB

BC

Author:  SlantSixDan [ Tue Oct 16, 2012 1:00 am ]
Post subject: 

Answer is "very important". You'll have obnoxious hot start/hot idle problems if the bowl vent doesn't open. The hairpin clip comes in a rebuild kit -- sounds like you need one. Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download.

Author:  64ragtop [ Tue Oct 16, 2012 8:18 pm ]
Post subject: 

Thanks for the kick, Dan and the link. When I read the relevant section, I found this:

"Bowl vapor vent adjustment must be to specification. If valve doesn't open to specifications with throttle valves seated, bowl vapors can't escape freely and this may cause hot hard starting. If it opens too far, or hangs open, it will allow an external vent to the bowl. This increase in bowl pressure causes a rich mixture resulting in a loss of mileage."

There's a bunch of carb function info there too, some of which I may retain. So, it seems in addition to the curb idle foul-up & the missing choke pull-off link and no bowl venting it's a wonder that the car ran at all!

Funny thing though, I found a fresh rebuilt BBS locally, and it is missing that hairpin clip, too. It sure looks good, but probably would have been plagued with the problems mentioned in the quote. Fortunately, I do have a rebuild kit. Which opens up another can of worms.

The adventure continues....

ATB

BC

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