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05-09-2019, 08:27 PM | #1 |
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Join Date: Jan 2019
Location: Florida Panhandle
Posts: 585
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Carb Inlet Valve
Went through three viton valves trying to get one that would not allow the carb to drip when the engine is not running and the tank shut off is open. It takes a few minutes but every time, the carb starts to drip after five minutes or so. No problem when the shut off valve is closed. Do more carbs tend to drip than not ? How common a problem is this ? Could the problem be something other than the inlet valve leaking ? Carb is a Zenith and has been completely rebuilt with new seals/gaskets, good float, float level set a .625 inch.
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05-09-2019, 10:55 PM | #2 |
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Join Date: May 2010
Location: Young Harris, GA
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Re: Carb Inlet Valve
See if you can remove the viton tipped needle part of the valve and look at the seat with a good magnifying glass. I have taken several apart and found little machining burrs and other rough edges in the seat that the viton tip seals against. So it does not seal. Clean up that seat and the viton tipped needle will seal.
When they are right, these viton tipped valves work really well. They really seal, and no, if the carb is right in all other areas, it will not drip. I use a light coating of non-hardening gasket dressing on the carb inlet valve gasket(s) so that you don't have to really tighten it up in order for them to seal well. That also stops the drips. I hope this helps.
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05-10-2019, 03:56 AM | #3 |
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Re: Carb Inlet Valve
I had the same problem with reproductions of company Snyders. (The case had no stamp.) I clamped the pin into a small hole-drill-engine and drilled the viton-needle against the needle-seat into brake cleaner at low speed and very low pressure. Very dense now.
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05-10-2019, 07:49 AM | #4 |
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Location: St Charles , Missouri
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Re: Carb Inlet Valve
I was going to wait and see what others say here but am going to put my 2 cents in now in hopes of gaining feedback. I buy them about 10-20 at a time and find that only about 6 out of 10 hold vacuum which is how I twatcthen before install. I’ve found if they don’t hold vacuum they leak. I open every one of them and haven’t found shavings in years. It’s a non issue today but they still don’t hold and yes, when they don’t hold vacuum they do in fact leak.
Some of the older steel tips still sometimes seem to be the best. I have even done a very light small tap with the smallest hammer to tap some steel units to get them to seat and his has done the trick more than half the time . Do Not do this to Viton seats or you will destroy them. I would like to hear experience and feedback as I feel the current seats don’t always sewl and fuel level rises overtops the jets. Larry Last edited by larrys40; 05-10-2019 at 09:26 PM. |
05-10-2019, 10:42 AM | #5 |
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Re: Carb Inlet Valve
"twatcthen"
Love it ! ! Paul in CT |
05-10-2019, 10:54 AM | #6 |
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Location: Largo Florida
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Re: Carb Inlet Valve
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In the past I've lapped the metal valve/seat with very fine compound. Toothpaste can also work. |
05-10-2019, 11:14 AM | #7 |
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Location: Glide, Oregon
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Re: Carb Inlet Valve
I would just like to add that even tho my float valve holds I never let my car sit with the S/O valve open. The float valve is meant for level control, not long term shutoff.
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05-10-2019, 11:24 AM | #8 | |
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Re: Carb Inlet Valve
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