Several days ago, there was some discussion about whether it was normal to have to richen the mixture upon starting a cold engine. I said that both of our T's liked to be richened 1/4 to 1/2 a turn (Summer and Winter respectively) to start, but began to surge after less than a minute, but smoothed out upon leaning the mixture back to normal run position. Jack asked that I take a look at my needle. I had not made time to do this until this evening, but I finally did it. I see nothing amiss with it. Here is a picture. Tell me what you think.
Looks kosher from here.
Looks good,but you still have not found problem..
I have no explanation for why some folks don't have to do it, but like I said before, I don't consider it a problem. I think it is normal. Later carbureted cars held their chokes partially closed, effectively richening their mixture, until the engine warmed up. Modern fuel injected cars richen their mixture by computer control when the engine is cold and lean it as it warms. I don't see why a T should be any different. What does baffle me is why it takes such a short period of time before it wants to be leaned.
But if I don't.....it will burn out the priming charge and die. Choke it again, and it will start on the next pull, and run for a few seconds and die. Over and Over. Classic sign of needing the mixture richened (I've played with too many model airplanes not to recognize this symptom.).
Hal's needle looks good.
If yours looks like this, here's the fix from the MTFCA carburetor book:
I do not know exactly when they started and stopped using the adjustable mixture control but it was used on at least 20,000 000 Fords! When Henry said two bolts in the Model A carb was one to many you think the adjustable mixture was still there if not needed????????????????? Bud.
every motor is a little different so certainly adjustment is a good thing. one little spec of dirt in a passage? adjust it. two little specs? adjust it again. normal, and it will give you lots more miles untill too many specs and you need to clean it out. one of my friends runs his model a with the valve closed all the time. i have never had one that will run like that, 1/4 turn maybe. ever had a neighbor whose lawn mower was running so annoying that you want to run over and tweek the main jet?
Hal - Maybe the difference has to do with other "variables" that we haven't considered? Some run a heat stove and some don't, some might have float level a bit towards low acceptable level, some towards higher but acceptable level, and something I've always wondered,......because there's really no way to see it, how do we know if the needle is "PERFECTLY" centered in the seat? Just sorta' "thinkin' out loud".......harold
While I'm "thinkin' out loud", being a 4th generation railroader, this reminds me of something I remember by Dad and my Grandfather talking about (as well as a lot of old "rails" since then) that you could put three (or more) IDENTICAL steam locomotives side by side, and they would all fire differently! Any seasoned steam locomotive fireman will tell you that some like the coal piled up at the back of the firebox, some like it piled in the back corners, some like the fire level, etc, etc. No rhyme or reason to it,.....just how it is! And as we all know, like steam locomotives, all Model "T's have their own personality, right? Probably no real answer for it,......harold