I just get the 1926 touring out of the barn after his winter sleep.
Last year it was running fine without any problems. Now it was hard to make it run right, she was running or to rich or to lean and it change during the test run without touching anything. Back home I took the carburetor apart thinking there was some dirt in the carburetor but it was as clean as it could be.
I looked further and saw there was some play on the adjustment needle. The steel section can be freely moved out of the brass part for about 1mm.
I think this was the reason why the engine didn't run right. With a few taps with a hammer ( best tool on a model T) the needle was blocked but will it stay???
Is there a way to fix it permanently or is it better to order a new needle.
Depending on which carb you are running as I recall if it's an NH the threads for the adjuster are in the body and the brass nut acts as a guide for the later carbs using the universal. You could try pinching the clamps on the needle tighter and also position the control rod so the tear drop is at the bottom or close to it when you are at your best setting. The tear drop on the knob acts as a counter weight and will want to work it's way to the bottom from the vibration of the car when things are loose.
If you used the hammer on the brass guide you could be putting the needles out of center by forcing it to one side.
Yeah, lay off the hammer Andre and say which carb your using.
It just takes a minute to solder the steel part into the brass. Pull it out, clean it well, clamp the threaded section at an angle and heat it so a drop or two of solder will run in the hole, install the steel section and heat. Make sure you don't get too much solder so it runs down and gets in the threads. The threads, by the way, are 1/4 x 32 t p i. They were not soldered at the factory, just pressed in and this is a common problem with them. Some of the adjusters are hard brass and don't have the separate needle but many do. Easy fix.
If it has come loose once it will come loose again if you don't solder it.
here few photos of the rebuild a few years ago. It is a 1926 NH Swivel carburetor.
Stan I will try to solder the needle as you told.
I will post some photos how i did it.
If you look at the lower left hand corner of the first photo you can see the needle that is in this carb. Whoever is repoping them isn't pinning or soldering the steel part of the needle into the brass. Since they are using soft 360 brass it doesn't take much for the steel to get loose in the brass. I try to find good old ones and retip them if the threads are good or just make a new on out of far more expensive and harder to machine Silicon Bronze.
I think what Andre is talking about and his hit with the hammer might be just the right thing to do to fix the problem, or a squeeze with a vice grip might be kinder to it.
On the NH or Kingston L4 for a 25 or early 26, and which has quite often been used as a replacement for the vaporizer, the needle has a steel clamp which goes around a brass cylinder which is screwed into the carburetor. The steel gets worn or bent and allows the needle to rotate from the vibrations of the running car. A squeeze on the steel while the needle is out of the carburetor, will tighten it up and keep it from vibrating around. I have done this to mine too.
Might work, in my experience the only thing that will hold them is solder. A lot of the repops are pretty sorry when it comes to tolerance and press fit -- which is what these are.
As promise here a few photo's, how I fixed it.
Yesterday I made a few taps with a hammer on the brass side of the needle and the point was blocked. This morning I tried to pull the steel part out but it was block so I decided to put some solder on the it to fortify the repair.
After I clean it up.
The nut over the needle is an old one I put on to protect the tread.
Hope it will stay.
Thanks Stan and Norman for the advice.
After hammering and soldering I would be worried that the needle assembly might no longer be pointing straight. The outlet hole in the spray nozzle is a small target and you cannot see how well the needle point is centered down there when you assemble the carburetor. The better the centering of the needle in the spray nozzle the better the cone shaped distribution of gas droplets will be and the more uniform in size they will be for vaporization. Does anyone have a good procedure for checking spray needles to insure they are co-axial from top to bottom?
I chuck them up in my Unimat or other small lathe and turn them, tap the high side with a little brass hammer until they run true. You could do the same thing in a drill press if you don't have a lathe.
For cleaning the solder I fixed it with the steel side in a static drill and made it turn. It didn't wobble so I think it is strait, I don't have a micro meter to check it for sure but during the test drive It run better as the last drive last year so the problem will be there since last year.
I will see during the weekend. The weather broadcast says it will be fine to go for some ice cream or pie and coffee.
Put a spare carburetor under the seat and will come home anyway maybe with dirt hand but the ice cream I will have.
Spoken like a true Model T fanatic. "I WILL have Ice Cream."
Just getting home from the Sunday afternoon drive AND.... I Had My Ice Cream !!!!!