Unfortunate Discovery

[Jacob Mangold]

Hello Forum. This evening I was tinkering around with the old NH off of my TT. It has been dribbling out of the carburetor recently and I suspected it was the needle housing for the needle valve on the inlet. I suspected this because it’s the only carburetor part I have not switched out. Reason being that there was some sort of sealant or cement holding the float in that someone must’ve done as a “repair” back in the day. Back when I was pulling my TT out of mothballs I figured I’d leave it if it works right because often times you don’t win fights you go out looking for. Like the old saying “If it ain’t broke, don’t fix it.” Anyways the carburetor worked good until recently. Now, no matter the float height, the thing wanted to leak. It doesn’t help that every gasket I get from the suppliers seems a bit too small and I end up having to soak it to make it fit. So finally, today I was fed up with the leaking and decided to remove the original needle housing and I was met with a not so good surprise. The needle housing seems to not be from an NH and the original needle housing threads are gone from the carburetor. So to put it shortly, my Holley NH carb body is essentially a paperweight. With that being said, I am going to need a new NH body. I don’t want to buy a new carburetor because I have all new NH parts from my original carburetor and am more than capable of rebuilding it. If anyone can help me out or point me in the right direction it would be much appreciated. I’ll post some pictures of my little catastrophe as well.

Thank you, Jacob Mangold

[AndreFordT]

You can try to fit it with a Heli-coil and a new seat.
I did it before and it works for me.

Good luck
Andre
Belgium.

[Mike Silbert]

Jacob,

That does not look like the right shape seat.
It looks like someone tried to epoxy a seat from something else in there.
But why?
Did they not have the right one?
Bad threads?
Rust?
Other?

I would try heating it and see what is actually in the hole.
It might be savable if it cleans up good enough.
Mike

Screenshot 2026-02-17 071441.jpg (23.24 KiB) Viewed 1164 times

[Moxie26]

Looks similar to a Holley G needle and seat part in his NH carb. Definitely wrong part.... Since the seat is made from brass, maybe those threads were distorted by the cast iron carb body, and the carb casting can be reused after cleaning and inspecting.

[Scott_Conger]

your valve looks very much like it is from a Kingston L-4, and you're correct, the core is now shot, since so much metal was removed to squeeze the much larger threads into the hole. I have all the respect in the world for Andre, but here in the US, NH carbs are really too plentiful to try to repair the casting - in fact, I'm pretty sure there is not enough "meat" left down in the hole for a helicoil to even go into since that material had to be removed to fit the body of the valve.

Someone is going to jump in pretty quickly to get you a good core - don't fret.

[John.Zibell]

Take the carb body and new needle seat to a machine shop. They should be able to sleeve, helicoil, or time sert the body to accept the new seat. I do recommend getting the needle and seat from Scott Conger as it allows more flow that stock.

[TXGOAT2]

Get a good casting and rebush the throttle shaft and install a high flow float needle and seat. Make sure the idle passage is clear. Good fuel flow is especially important in a TT to assure full power, and a smooth, slow idle assures good engine braking and good overall drive-ability.

[love2T's]

Here's where the "three R's" come into play... "Replace, Replace, Replace"!

[Jacob Mangold]

Yeah the core is done for. The threads are non existent and blown out. When I look down the passage, it’s straight through. The needle housing was not threaded in anywhere and was just epoxied in place. Your guy’s guess is as good as mine when it comes to why. Hopefully someone who is willing to part with an NH body comes along.

Thank you, Jacob Mangold

[Mark Gregush]

NH cores are a dime a dozen! If you used Facebook, there is a guy on one of the T parts for sale pages that has a number of NH cores.
Click on his name to rest of listings. https://www.facebook.com/commerce/listi ... attachment
You could also place and wanted ad or check out eBay.

[Jacob Mangold]

Thank you Mark. I’ll have to shop around some. I’ll put up an ad in classifieds and see what comes of it. Facebook works too but I’m weary of scammers if I’m not meeting the person face to face. The forum is definitely the first choice when it comes to reliability.

Thank you, Jacob Mangold

[ModelTWoods]

EBAY is also a good source for Holley NH carburetor bodies and/or complete cores. There's almost always some on there at any time.

[Mark Gregush]

Thank you Mark. I’ll have to shop around some. I’ll put up an ad in classifieds and see what comes of it. Facebook works too but I’m weary of scammers if I’m not meeting the person face to face. The forum is definitely the first choice when it comes to reliability.

Thank you, Jacob Mangold

Re Facebook, check their profile and see how long they have been on Facebook along with reading their posts. Also no matter how long they have been around, use Goods and Services for pay-pal. Some are fine with it, some that think they are hiding their income even though they sell a lot, only want to use F&F. I offer to pay the fees, if they say no, I pass on that great deal. Think the fee is something like 3.65%. The fees using Goods & Services is a lot cheaper than seller fees on eBay and many sellers on eBay roll the fees into the price.

[Original Smith]

There is no reason to use a sealant in a carburetor! Use the factory gasket only.

[Mark Gregush]

There is no reason to use a sealant in a carburetor! Use the factory gasket only.

I agree with Larry with one exception, the gasket supplied for the needle valve seat is too hard in my opinion and would make my own lead gasket after making sure any old gaskets were removed.

[Scott_Conger]

The irony is that no one suggested using sealant.

Sealant was used by some bodger to smash the wrong valve into place and is the situation as-found, not a plan to move forward.

[John kuehn]

If you call Lang’s or Chaffins they may have some good used NH cores they will sell. Lang’s has good used parts to sell they don’t advertise. Good luck.

[speedytinc]

How does THIS happen? ....Someone decides to replace a leaky needle & seat unit. They put an ill fitting seat removal tool, like a worn out screwdriver blade. Then chew up the seat notches, so it cant be unscrewed. Next they try a screw extractor. It wont bite & expands the seat making removal impossible. Next they try drilling the seat out, but ruin the threads. Last chance, adapt another seat from some other carb.

How do you prevent this?..... Use an oxy/acetylene torch & heat the body around the threads to cherry red. Let cool. Most of the time it will remove with fingers only. (once the varnish is burned off)


This body is fairly easily repairable. I would not take the time as long as I can still find cores for under $20.
If I had to pay $99(Ebay prices), I would wait for another 1 or 2 to appear & fix all 2 or 3 @ the same time.
I wouldn't throw it away.

FYI, Jacob. That carb body is incorrect for a 24.
Try to find another core with a short throttle arm & short choke arms.

[Jacob Mangold]

FYI, Jacob. That carb body is incorrect for a 24.
Try to find another core with a short throttle arm & short choke arms.

My truck is actually a 1926 with a 1924 block in it according to the number on the frame and different number on the block if that makes a difference. Funny enough about the method you mentioned for needle seat removal is exactly what I did, except after I got her nice and hot it still wouldn’t twist out via screwdriver so I ended up resorting to a pipe extracting tool. When I went to tap the pipe extractor in I actually knocked the seat in and confirmed my suspicions that something wasn’t right. Sealant where it shouldn’t be necessary almost always tells the same story. I see and have to fix boogered up stuff constantly at work and now I can’t even escape that on my own stuff . It baffles me some of the stuff I’ve seen. Like there is no way the guy who was working on it before me thought to himself “Yeah that’s definitely going to work like it’s supposed to and it is going to last as well.” Words to live by: Do it right or don’t do it at all!

[RGould1910]

Is that a Perfecto I see in the background?

[Jacob Mangold]

Is that a Perfecto I see in the background?

That is a defunct Model T starter, AA truck hub puller, and pieces to a TT ruckstell I plan on putting together eventually in the background. I’m not familiar with what a perfecto is. Go ahead and enlighten me.

[Mike Silbert]

Jacob,

The Perfecto predates the Hall Scott / Ruckstell rear axle assembly.
The Ruckstell book - https://www.modeltford.com/item/R6.aspx - Goes over the history.
I think of it as a generation 1 part and an evolutionary step getting to the Ruckstell we are familiar with.
The only problem I know of it is not common and hard to get parts for if needed.
Those who run them say good things.

Links to some details
https://mtfca.com/phpBB3/viewtopic.php?t=1041
https://www.mtfca.com/discus/messages/2 ... 06352.html
https://www.mtfca.com/discus/messages/1 ... 1278436118
https://www.mtfca.com/discus/messages/5 ... 1206897194
https://www.mtfca.com/discus/messages/1 ... 1274712112

Mike