Those New Original Style NH Needle And Seat Valves Leak

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Model T Ford Forum: Forum 2015: Those New Original Style NH Needle And Seat Valves Leak
Top of pagePrevious messageNext messageBottom of page Link to this message  By James A. Golden on Thursday, August 06, 2015 - 09:21 am:

A friend and I have rebuilt 6 or more NH carburetors with those new original style needle and seat valves and they all leak, when properly adjusted, according to the book!

Are we over-looking some detail?

Does anyone understand the problem or know of an easy fix to the problem?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Thursday, August 06, 2015 - 10:14 am:

Are they leaking through the valve, or around it? Stan pointed out that sometimes the gasket behind the valve doesn't seal and you have to smooth the bottom of the hole.


I think the third needle here is original. Do the new ones look like it? After having a couple of the rubber tips get stuck, I replaced them with the old type.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Keith Townsend ; ^ ) Gresham, Orygun on Thursday, August 06, 2015 - 10:19 am:

Steve-
I think the third type is the original from a Holly G.
I think the fourth one is the original from the NH.

-Keith


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ken Todd, ............Red Deer, Alberta on Thursday, August 06, 2015 - 11:00 am:

Try these links,

http://www.mtfca.com/discus/messages/506218/546420.html?1433267640

http://www.mtfca.com/discus/messages/506218/508178.html?1422895026


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Georgetown TX on Thursday, August 06, 2015 - 11:15 am:

Steve is correct, that is an original NH needle. I think it would work in a Holley G as well.

See here for how to polish the needle. After polishing the new needle, install it in the seat, in the carburetor, and give the needle a light tap with a small hammer and 1/4" brass punch. That will cause the needle and seat to deform to fit one another.

More info here:
http://www.mtfca.com/discus/messages/411944/469501.html


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ted Dumas on Thursday, August 06, 2015 - 12:44 pm:

You can use Royce's technique with your old needle and seat and you will very likely solve any leakage problem.


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