The Ford Barn

khschs · 12-01-2021, 02:14 PM

I fired up the engine today for the first time in a long time. I have dual 97's on it. I noticed the rear carb was dripping gas in the right venturi at fast idle. The source of the leak seemed to be around the emulsion tube. The other three were dry. This doesn't seem right, what is the fix?
Thanks Keith

Bored&Stroked · 12-01-2021, 02:41 PM

Usually this is because you do not have the throttle blades synchronized . . . so the rear carb is seeing more vacuum than the front. There is enough to start pulling fuel up the emulsion tubes. For any situation where you're running two or more carbs, it sure makes sense to buy a 'UniSyn' device. I've had one for 45+ years and I use it on every dang flathead that I build (all have 2 or more carbs).

You can buy them from Edelbrock - though it is a lot cheaper on Amazon:

https://www.amazon.com/Uni-Syn-Carbu...15972692&psc=1

khschs · 12-03-2021, 06:51 PM

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Thanks for the tip. I pulled the bowl portion of the carbs off leaving the bases in place, I found that very little adjustment was required to sync the butterflies. I replaced the emulsion tube from a donor 97.The problem seems to be a thing of the past. Thanks again,Keith.

12-01-2021, 02:14 PM	#1
khschs Member Join Date: Mar 2012 Posts: 70	97 internal leak I fired up the engine today for the first time in a long time. I have dual 97's on it. I noticed the rear carb was dripping gas in the right venturi at fast idle. The source of the leak seemed to be around the emulsion tube. The other three were dry. This doesn't seem right, what is the fix? Thanks Keith

12-01-2021, 02:41 PM	#2
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,062	Re: 97 internal leak Usually this is because you do not have the throttle blades synchronized . . . so the rear carb is seeing more vacuum than the front. There is enough to start pulling fuel up the emulsion tubes. For any situation where you're running two or more carbs, it sure makes sense to buy a 'UniSyn' device. I've had one for 45+ years and I use it on every dang flathead that I build (all have 2 or more carbs). You can buy them from Edelbrock - though it is a lot cheaper on Amazon: https://www.amazon.com/Uni-Syn-Carbu...15972692&psc=1

12-03-2021, 06:51 PM	#3
khschs Member Join Date: Mar 2012 Posts: 70	Re: 97 internal leak Sponsored Links (Register now to hide all advertisements) Thanks for the tip. I pulled the bowl portion of the carbs off leaving the bases in place, I found that very little adjustment was required to sync the butterflies. I replaced the emulsion tube from a donor 97.The problem seems to be a thing of the past. Thanks again,Keith.