Poured gas into carb, dripped a little out of shaft....

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sc2dave
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Poured gas into carb, dripped a little out of shaft....

Post by sc2dave » Mon Oct 09, 2017 12:00 am

When i poured a little bit of gas down my carb, I noticed a little bit came out of the throttle shaft. Is this normal or the seals are very worn? I don't have any big problems with this carb.

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Re: Poured gas into carb, dripped a little out of shaft....

Post by Circlotron » Mon Oct 09, 2017 12:21 am

Gasoline has fairly low surface tension so it is able to penetrate fine crevices easily. Wouldn’t take very much of a gap for it to find its way out.

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Re: Poured gas into carb, dripped a little out of shaft....

Post by tresi » Mon Oct 09, 2017 12:34 am

I haven't ever taken apart a carb that had seals on the throttle shafts. Gas can seep through if they are worn. Signs of worn shafts are excessive idle speed even with the screw backed out or a throttle that hangs up when closing.

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Re: Poured gas into carb, dripped a little out of shaft....

Post by lefty o » Mon Oct 09, 2017 12:36 am

tresi wrote:
Mon Oct 09, 2017 12:34 am
I haven't ever taken apart a carb that had seals on the throttle shafts. Gas can seep through if they are worn. Signs of worn shafts are excessive idle speed even with the screw backed out or a throttle that hangs up when closing.
actually them crappy aluminum holleys that the top came off of had plastic/teflon seals on the shafts.

sc2dave
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Re: Poured gas into carb, dripped a little out of shaft....

Post by sc2dave » Mon Oct 09, 2017 12:44 am

I don't have a lot of experience with holleys, so I thought all of them had those plastic sleeves as bushings.

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Re: Poured gas into carb, dripped a little out of shaft....

Post by tresi » Mon Oct 09, 2017 12:50 am

lefty o wrote:
Mon Oct 09, 2017 12:36 am
tresi wrote:
Mon Oct 09, 2017 12:34 am
I haven't ever taken apart a carb that had seals on the throttle shafts. Gas can seep through if they are worn. Signs of worn shafts are excessive idle speed even with the screw backed out or a throttle that hangs up when closing.
actually them crappy aluminum holleys that the top came off of had plastic/teflon seals on the shafts.
You I did take apart a some type of plastic bushing. I didn't really think of them as seals but as bushings but I guess they could be used for sealing.

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Re: Poured gas into carb, dripped a little out of shaft....

Post by peejay » Mon Oct 09, 2017 3:45 am

If you ever have a chance to use a smoke tester, cap off a Holley air horn and smoke test the intake. You'll find air leaks through the throttle shafts, half the screw holes in the body, the choke rod passthrough, all sorts of places.

If you're concerned about unfiltered air getting into the engine, it's a REAL eye-opener.

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Re: Poured gas into carb, dripped a little out of shaft....

Post by pamotorman » Mon Oct 09, 2017 9:03 am

sc2dave wrote:
Mon Oct 09, 2017 12:44 am
I don't have a lot of experience with holleys, so I thought all of them had those plastic sleeves as bushings.
correct they are bushing for smoother operation. the holley shaft is .007/.008 smaller than the base plate hole to make sure it does not bind up. not all holley carbs have the bushings

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