I am having carburetor problems. Here are the symptoms.
1. Hard to start.
2. After driving for 10-20 minutes the car seems to run out of gas and stall.
I noticed that when trying to start it when I have it choked and crank it fuel spills out along the red arrow in the picture. It appears that fuel is actually coming out from behind the gold plate.
I was surprised to see this as I believed the plate was simply attached to the exterior of the carb and that there was no hole nor penetration down into the fuel chamber.
Currently Im thinking this carb is shot and I need to get a new one. Stromberg OF seems to be the best you can do. I have a 16 T roadster.
Any one have any ideas?
There is a vent hole under the data plate, so if the float setting is too high, or some contamination in the fuel prevents the float needle from sealing, fuel will come out from under that plate.
Running for a while (minutes) then stalling can be a symptom of fuel contamination. Are you running a new gas tank, or an original tank? Have you looked at the sediment bulb to see if it is full of crud? Are there particles in the fuel when you drain the carb bowl into a clean container?
Steve Jelf wrestled with fuel contamination from his original gas tank for a while, after several episodes he ended up buying a new gas tank. It's a long thread, but well worth reading from start to finish.
Michael, welcome to the wonderful world of Model T's. The carburetor on your car is a Holley NH, generally regarded as the best of the standard carbs. The brass plate covers a vent hole and under heavy choking you can expect fuel to be coming out from there.
You may have a fuel starvation problem. If the car runs well and then begins to struggle, it may be that your fuel delivery is compromised. Often this is caused by a fuel filter fitted in the line from the tank. The gravity feed system on a T will not work successfully with a filter in the line. A glass bowl sediment catcher may be OK.
That said, if your car will run 10-20 minutes before it dies, it must be a very limited restriction.
Hope this helps.
Allan from down under.
Believe that's the vent hole under (behind)the plate. If fuel is rising to that point it usually means a bad needle/seat or a holed float. Of course either of those would also mean a constant flow of fuel onto the ground because the flow is constantly on so perhaps not that. Your stalling could very well be a dirty tank/fuel system. Your leak indicates a carb re-build is necessary for whatever internal problem has developed in there to cause a leak. Your existing NH is fine for T use. Cheap & easy to repair with all necessary parts available. Of course if you want to go for the $ for something else it's your buck but I still think a system cleanout is needed.
Has this trouble recently developed, or is this a new to you car? Sounds like excessive choking on the cranking problem and maybe vapor lock on the stalling issue. I have had to relocate the fuel line to stop vapor lock.
What do you have the float set at? If it is set too great, the float will close the needle valve before the bowl is full and may starve the engine of fuel. If it is set too little, the float will fail to close the needle valve after the bowl is full, allowing the bowl to overflow out through the vent holes.
Proper setting: On the side opposite the hinge, it should be 15/64" from the machined flange to the flat underside of the float. You can make a measuring gage as per the attached illustration. Jim Patrick
Im running a new gas tank and I have a gravity fuel filter in line before the carb
Just got done taking the carb off and spraying it out with carb cleaner, hitting with compressed air, etc. All clean. Put a new fuel filter on.
When trying to start I noticed fuel spilling out when cranking it choked.
First,lose the filter,and did you shake float to see if it is good?
What Jack said, doublecheck the float to make sure it doesn't have a pinhole leak, doublecheck the float level, then try it again without the filter.
Be sure to report back and good luck!
(Message edited by cudaman on February 05, 2017)
Sounds like a needle and seat issue. What is the type and condition of the needle?
Also check float to see if it is full of gas, it can happen. It will slosh around when you hold the float and shake it.
Sounds like your float may be too close to the ceiling of the bowl chamber so that the bowl fills too much before the float closes the needle valve shutting off the fuel flow. Adjust it to 15/64" as instructed above. Jim Patrick
One other possibility - if the carb has a Grose jet in it, that could be a cause of flooding. Replace the Grose jet with a stock needle and seat. The current reproduction needles are machined too roughly, be sure to polish the tip of the needle to help it seal better.
carb is a rebuilt from Snyders.
When I was cleaning it I shook it and I could hear the float going back and forth.
Take the float bowl off and check for a Grose jet, some of the rebuilt carbs come with them. while the bowl is off, remove the float and shake it to see if there is any gasoline sloshing around inside it. Even though the carb is a new rebuild, things happen - new floats can have pinhole leaks, Grose jets get installed, float level may be incorrect.
I know that in a perfect world, a fresh rebuild from the vendors would work perfectly out of the box, but sometimes a fresh rebuild needs some help / adjustments.
Sounds like float height issue to me. These other guys might have a better idea but I would check that first. Tim
Absolutely hating the carb right now. Been trying to start it for 30 minutes. My arm is sore. These NH carbs are crap. Sorry just venting my frustration. I am really considering sinking the big $ into a stromberg in hopes that it will work far better than these NHs that work ok one day and then fail miserably the next, and the next, and the next.
I must respectfully disagree. They are not crap! The Holley NH Carb, when rebuilt and adjusted correctly, is, to me, the best and most reliable Model T Carb ever made. I have had the original NH in my '26 coupe since 1970 and it has never let me down. Just my opinion. Jim Patrick
Michael I have a 1919 Roadster, 21 Touring and a 24 Coupe. Each one starts a little different even though the settings are pretty much the same.
Probably something simple about your carb causing the issue.
If the gas is coming out the hole under the pat. plate its pretty much has something to do with the float in my mind.
One of my T's starts better when I turn the needle valve about 2-2 1/4 turns. When it starts I turn the needle back to about 1 1/2 turns out.
Starts easier that way with out choking it. Don't ask me why. Just does. Try yours that way and see.
Both of my cars are Nh and really start easy. Not big power but really smoother runners and a easy start. Hope you get it fixed. Mine to run best at slightly different needle valve settings. Just the way mine have work. Tim
Yes, from what I've read the Stromberg OF is a great carb. That's why it's so expensive. But your ire at the NH us misplaced. It may be the best standard equipment carburetor Ford used.
Your fuel starvation is likely to be due to:
1 Dirt/debris/crud in the fuel. Your new tank goes along way toward eliminating this issue, but it isn't the full story.
Sometimes a bit of packing a can get lodged in the line and obstruct the flow.
2 The presence if a filter. As the other guys have said, ditch it.
The overflow can be caused by several things.
1 Grose jet;
2 Leaking float gets fuel inside;
3 Float adjustment wrong;
4 Fuel leaking around the float valve. Two things here. The surface behind the seat may not be smooth. Sometime in the last 90 years rust or some other malign influence may have made it uneven. Also, the little gasket supplied with the seat may be too hard to seal properly. This seems to be a problem lately.
5 Needle tip rough. That's also been a problem with recent ones. Smooth it as Mark says.
Here's how balky, hard-starting, and unreliable an NH carburetor is: https://www.youtube.com/watch?v=6ZzX1Wwrkq8.
Once again: the Carb only leaks when he's cranking. Even if it has a Grosse jet setup it's not leaking when he's sitting still. Same goes for the float: if it was holed or set way too high he would leak constantly. That's not his complaint. Read the post. He says he took the Carb off and sprayed & blew air into it. Sorry but that didn't accomplish a thing. You need a rebuild. No two ways about it there's an internal problem/blockage. Your stalling still sounds like a flow problem. Dirt, clogged screen, plugged tank vent in the cap, low fuel level in the tank, sect.
Well, since it is midnight on Sunday, I just got back from a 1400 mile weekend trip of playing music until 4 in the AM, drinking good whiskey and dancing with good looking cowgirls, I am too tired to do any more than offer one small opinion.
The Holley G is the best stock carburetor ever supplied on the Model T.
In my humble opinion. Based on working on Model T's since 1954 and rebuilding well over 1,000 Model T carburetors and another 1,000 or more for other cars, trucks and tractors.
The inline fuel filter will cause the symptoms described. Get rid of it and all will be better.
Since I do my own carbs the Stromberg presents a problem to me. That is the lack of re-build parts. None of the big boy parts houses seem to carry any. Add that to the huge out lay for an unrebuilt core and you're dug a nice deep $ hole. I believe there are reputable people that re-build them but again buying one re-built out right is money better spent elsewhere especially since I'm assuming you don't know how good they run with an NH to begin with. Not knocking the big boys but you just don't know what you're getting buying this kind of thing from them as in what was actually done. Have you contacted the seller you bought it from? Since you have a leak problem there might be some recourse there.
Or you can PM me for a calm & to the point discussion.
If you have the stock cast iron bowl and valve under the tank,there should be NOTHING between it and the carburetor but a completely clean and uncrimped fuel line. Those filters will slow fuel down to much much.
If the screen is clean and such, with a new tank and clean gas can, you don't need another filter.
The only other thing that crossed my mind is a stuck intake valve letting compression back into the intake and cause fuel to belch from the carb.
But for the money, Nh is a good carb that is easy for the average person to repair.
And remove the float completely from the carb. Shake it near your ear. If you hear "sloshing", then it is bad.
Snyders will look after you if it has a warranty. Just be polite and explain the issue.
Now this link goes to a page that explains the same problem you are having with stalling but with a different type engine. In this case, 25 microns difference in filter material makes the difference of run or no run correctly.
Read it thru.
Im not looking for business since i already could work 18 hours a day 7 days a week doing carbs. However, stromberg sold close to a million OF carbs at about 16 bucks each from 1922 to mid 26. There was and is a reason they sold them. At the time there were well over 100 companies making accessory carbs for fords. Ford was paying 30.5 cents for the nh and a replacement nh at the dealer was about a dollar. Decide for yourself.
Part of fords use of the nh was based on production speed as well as cost. There is virtually no machining on the nh, they could crank them out by the thousands a day. The holley g is more complex and has many more parts, much more machining and much higher skill level and time required for assembly than the later carbs, hence much higher cost. The nh was also cast of iron instead of brass, which cost much less. By 1921 the cost of brass had doubled due to far less scrap brass being available as munitions were not being produced or scrapped.
Off to the shop, im tired, going to be a long week.
Stan. Can you post a picture of the Holley G? I have never seen one. Thanks. Jim Patrick
What was the problem that you had that caused you to replace the carb? If I crank mine with the choke closed, it will spit gas out the vent hole on the second pull. If I pull it a third time with the choke closed, it is now flooded. It might not need as much choke as you are giving it.
A NH may be cheap, but it should certainly work without giving the kind of trouble described.
Since it's a repaired carb from a vendor, I think it may have a Grose jet as some have already suggested. That would explain all the trouble. They may work in other applications, but in Model T's, especially with under the seat tanks, they're trouble. Check if the valve in the carb has a ball like this:
Then it's a Grose jet and needs to be changed to a standard type needle:
But as you can see, the repro needles available needs some smoothening until they work as they should. Rotate the needle with an electric drill and smoothen with a stone or fine paper, smack the needle into the seat with a small hammer for proper fitting. Then it should work - if you have removed the inline filter ;)
(there is already a filter in the sediment bulb at the tank)
If you go to the encyclopedia that's on this website and click on carburetor, there are good pictures of the carbs used on the Model T. The Model G is among them for those who want to see one.
I just rebuilt mine and the needle on mine has a sharp neoprene rubber tip and it gets a good, immediate seal when the float raises it up into the seat. Jim Patrick
Good advice. The NH is a good carb, most of the problems with the NH, IMHO, come from the use of the Grose jet, which has no way to pull the needle off the seat if the gas is even the slightest bit sticky as a lot of it is today after it sets for awhile & from the repop floats made in India that are so heavy they do not rise far enough or have pressure enough to cause the needle to seal.
Bear in mind that the pressure against the seat is caused by the displacement of the liquid in the bowl. The lighter in viscosity the liquid is, the less pressure the float has against the needle. A float in water or kerosene has more pressure than it does in gasoline. Combine that with the crap needle and seat sets many of vendors sell, the hard gaskets that won't seal and the vent hole in the bowl not being opened during many "rebuilds" and they will bring a grown man to tears.
If you search back you can find a post on making a lead gasket for the seat, smoothing the tip and whacking it to get it to seal and a bunch more posts on cleaning ALL the passages.
All that said, my guess is that your vent hole from the bowl to the outside is blocked.
Michael - As many have suggested, the inline fuel filter may be your problem. Royce has assured you that if you "get rid of the filter and all will be better." I agree that the filter could very well be the problem, but I would have said,..... "all MIGHT be better"! Besides the inline filter that Royce absolutely KNOWS is causing the problem, I would consider the possibility that that new gas tank you mentioned is properly vented. Unless I missed it, I don't see where anybody mentioned checking your gas cap. There is a tiny vent hole that MUST be clear, or the gas tank could be slowly building up a very slight vacuum that could be causing your problem,.....FWIW,...... harold
Dang! Meant to say,.... "NOT properly vented". And I was typing at the same time you were Stan,.....sorry,....harold
Something which could be part of your problem and I don't think it was addressed above. Most of the Model T's had a gas tank under the front seat or under or under the back seat for a few. So if the tank is not full it will sometimes give the symptoms of running out of gas. This can be likely if you are going uphill. So if the gas tank is low try filling it up and see if it fixes the problem.
Update. Got it running today and drove it for an hour. Looks like the running out of gas symptom is solved by replacing the fuel filter. Switched from one that needs a fuel pump to one that is gravity fed. Old one was pretty dirty and I suspected it might be restricting the flow of fuel especially when the tank is less full and there is less pressure due to the weight of all the gas. I know a lot of you say take the filter out all together but I want to keep the carb clean.
As for the hard to start I only started 2 times today. The first took some time but when I shut it off to fill the tank at the gas station it started right up with minimal effort. All I can think of is some of the carb cleaner was still in there and was causing me pain till it cleared out. Once I got it running initially this morning I was able to drive it and get the mixture screw set right at the sweet spot.
I was also thinking that the breather hole in the gas cap might be getting blocked by the bottom of the seat. It seems the wood bottom to the seat would press right against the cap and prevent air flow in as fuel is flowing out the bottom. The pin hole is right on the top. Was thinking about drilling a second one on the 45 degree side.
I appreciate all the comments. Every time I post something on this forum I get a ton of useful info and often learn something new. I have been away for quite a while but am now back. Heading into spring I am planning on logging a lot of miles.
Lots of good advice already posted!!
Now I will add one additional item that I've learned from many years of playing with old cars; 90% of my carb problems have been ignition!! Hopefully you know that your ignition is in first class condition and you can just ignore my posting
BTW my dad always referred to steep hills as "7 gallon hills". For those who don't understand it means the hill is so steep you had better have at least 7 gallons in the tank if you are going to climb it without stalling (driving forwards at least lol)
Not to keep beating a dead horse Michael, but I personally believe, and I think others smarter than me would even agree, it is a waste of time and $$$ to mess with inline fuel filters at all, if you have either the original "potato" type sediment bowl that has a very fine screen in it. or, some of us who are not purists use a universal tractor type sediment bowl that also has the very fine screen in it, as well as a very convenient built-in shut off valve. (....available at most tractor or farm supply stores for less than twenty bucks). Here's the main point here, is than any little speck of rust or scale or whatever that is small enough enough to pass through the fine screen will also pass thru' any carburetor jet with no problem. And by the way, the universal glass sediment bowl even looks pretty good too,....almost, ALMOST,.... looks "period correct". FWIW,......harold
P.S.....at any rate, glad you solved the problem!
Les,...you only told Michael half a story,.....the way I heard it is that "90% of carburetor problems are ignition, and 90% of ignition problems are carburetor!" ..... harold (:^)
Your experience could well be different from mine
Les - Yeah,....it's that other 80% that pretty well covers my "experience" that may well be different than yours,..... ha,ha..... (:^)
Well at least the old NH holley aint as complicated as this #&@# thing!
This was my first 4 barrel Holley rebuild. Not as hard as I expected. But the old NH is much easier!
For Jim Patrick in Florida,
Holley G and Holley NH
Stan, I agree. I've got a Holly G on my 1914 -- original to the car -- and when properly adjusted there's nothing else like it