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Start a T on Magneto
Posted: Wed Dec 15, 2021 2:45 am
by rainer
Hello.
My Lizzy is a '16 with starter motor. It runs fine on battery and magneto.
Usually I switch to battery when starting by hands or crank, the I switch to magneto.
Once I tried to crank-start it on magneto to find out if this will work at all. I got this idea after I found out that the engine does not start on magneto with electric starter.
I think this is because the starter is turning the engine too slow for getting sufficient magneto output.
Can somebody tell me how to crank-start on magneto successfully? A short video, showing how fast to crank,would also be helpful.
Thank you!
Re: Start a T on Magneto
Posted: Wed Dec 15, 2021 5:16 am
by AndreFordT
To start on magneto.
First the magneto must work as it should be and second you coils must be fine tunned and in good working order.
I first prime the engine, 3 or 4 puls with ignition in OFF, choke pulled and the gas 1/3 down.
Second, set the advance 2 or 3 notice down.
Switch on magneto.
On or two puls should start the engine.
Good luck
Andre
Belgium
Re: Start a T on Magneto
Posted: Wed Dec 15, 2021 6:52 am
by Humblej
Starting on mag is the same as starting on battery for either electric start or hand cranking, except you must advance the spark a little for a mag start. Advance about 3 notches of spark and normal speed and style of cranking. Yes, a 1/4 pull up on the hand crank will start on mag.
Re: Start a T on Magneto
Posted: Wed Dec 15, 2021 8:50 am
by speedytinc
Whats the mag output? Must be weak. I have no such issues. Hand cranking takes a quick 1/4 turn after a choke prime cold & without when warm.
Starts as easy with the starter on battery or mag. You might want to test your coils on a HCCT to see what voltage it takes to start sparking. You could remove the plugs & have someone listen for coil buzz to see how fast you need to spin the motor. The last set of coils I tuned sparked @ 2V in the tester with a slow crank.
Re: Start a T on Magneto
Posted: Wed Dec 15, 2021 9:40 am
by rainer
Thanks for your comments.
Now I know what I did wrong.
1. I had the spark fully retarded (because I am a bit scared about a kickback).
2. Even with priming, I possibly pulled to slow to get a usable MAG output.
It was relatively cool weather and I have steel clutch disks installed. So the engine was a bit "stiff" to turn. But I will try again, when my Lizzy is out of garage.
Just a question if interest...
I use a 6V battery, so the voltage is between 6.2 and 6.8V. The engine starts very easily with starter (within 2-3 seconds) when I prime first (3-4 1/4 turns/pulls on crank). So I think I should crank fast enough to get at least the same voltage on MAG. Has somebody ever measured the generated voltage when pulling the crank "quickly"?
Thanks!
Re: Start a T on Magneto
Posted: Wed Dec 15, 2021 10:04 am
by Ron Patterson
Study this diagram and it will help explain why hand starting on the magneto is easier with the spark lever advanced a bit.
Also here is the Ford recommended starting instructions for early Model T's that had no battery.
Re: Start a T on Magneto
Posted: Wed Dec 15, 2021 10:25 am
by TXGOAT2
I have to advance the spark lever quite a bit, about 1/3 of its travel, to start on MAG with the crank. When using the starter I advance the lever no more than 3 notches, or not at all when the engine is warm. I have New Day style timer. I had difficulty starting on MAG with the crank until I (very cautiously) tried advancing the spark lever more than the recommended 3 notches. A brisk pull is usually needed. A magneto in good shape will facilitate starting on MAG, whether using the starter or the crank. I haven't tested mine fully, but it's apparently in fair condition. Proper oil for the season, and proper clutch and linkage adjustement will facilitate starting by any method, as will good coils in good adjustment.
Re: Start a T on Magneto
Posted: Wed Dec 15, 2021 11:14 am
by Norman Kling
Here are two things to consider.
1. Those 2 or 3 notches might be different on the early cars with the large lobes between the notches and the later cars with the grooves filed into a smooth quadrant.
2. The position of the timing when you originally set the timer can vary somewhat unless you are very careful to find the right spot. The rod length will differ with different timers and if you have loose linkage you will have play in the spark lever. And even the centering of the timer on the camshaft makes a difference.
So the sweet spot will differ for each car and can differ after servicing the timer or replacing the timer.
Norm
Re: Start a T on Magneto
Posted: Wed Dec 15, 2021 11:32 am
by Steve Jelf
Here's your video, starting both ways. Yes, you can pull slowly on BAT, but on MAG you need some speed.
https://www.youtube.com/watch?v=b5ycpdfIjDo
Re: Start a T on Magneto
Posted: Wed Dec 15, 2021 12:03 pm
by greenacres36
You didn’t mention what type of timer you had. It really doesn’t matter except if you have an I-timer. No matter what it will not start on magneto with one of those.
Re: Start a T on Magneto
Posted: Thu Dec 16, 2021 8:11 am
by rainer
Thank you for your kindly answers and the youtube link.
My timer - so I was told - seems to be a very similar to the original ford timer. Luckily I found a picture where it is good visible.

- Here you can see the front end of the engine
From what I see in the video, I think I know why it did not start. I had the spark fully retarded (left lever in uppermost position), as I do with electric starter, to be sure to not receive a back kick. With time I always set to fully retarded position as this worked with warm engine.
When I got my Lizzy, the timer was extremely wrong adjusted, but I didn't know that. I know the measurements only in millimeters, but the distance between the bolt center and timer ear in fully retarded spark should be 62mm, but it was 71mm. Therefore it did really hurt when I tried to crank-start, the starter motor also was not very happy, because the spark was always heavily advanced. Then I noticed this wrong adjustment and corrected it by bending the connecting rod. -> This goes into the section of "novice errors" 
Re: Start a T on Magneto
Posted: Thu Dec 16, 2021 8:57 am
by Charlie B in N.J.
The first time my ‘23 started dead cold on mag was after I redid the coils and had them set up on an HCCT.
Re: Start a T on Magneto
Posted: Thu Dec 16, 2021 10:27 am
by Steve Jelf
I've never set timing by measuring distance. I believe this is better: http://dauntlessgeezer.com/DG97.html.
Re: Start a T on Magneto
Posted: Thu Dec 16, 2021 10:31 am
by RajoRacer
There is a distance measurement in the Ford Bible for initial setting of a stock Ford timer. I won't attempt to hand start anyone's T without verifying type of timer and the distance between the timer rod eye and the timer clamp bolt - accidents CAN happen !
Re: Start a T on Magneto
Posted: Thu Dec 16, 2021 11:19 am
by rainer
Hi!
Yes this measurement is 61-62 mm (converted from Imperial measurement).
Lang's also sells a "timer gauge" for that, but a simple ruler does the same job. Simply measure from center of the hex bolt to center of the pull rod.
I already read "The Ford Manual" (this Q&A style book) and another one going a bit deeper into details, "The Ford Model T Car, its construction and repair, 1917 edition". I found this books as PDF in the Internet. They explained things very well. Somewhere inside one of them this measurement was written.
About accidents ... I already read a lot of warnings on back kicks, and how to correctly pull the crank (with left hand and grasped from outside, while right hand is on the fender) months before I bought my Lizzy. Of course, if one starts carelessly cranking it like a meat grinder ... this will hurt when spark is advanced.
I was simply too scared and retarded spark too much for MAG cranking. But this is trial and error on next spring - actually why should I when a BAT is available... On BAT I will still put the lever in uppermost position.
RajoRacer wrote: ↑Thu Dec 16, 2021 10:31 am
There is a distance measurement in the Ford Bible for initial setting of a stock Ford timer. I won't attempt to hand start anyone's T without verifying type of timer and the distance between the timer rod eye and the timer clamp bolt - accidents CAN happen !
Re: Start a T on Magneto
Posted: Thu Dec 16, 2021 6:35 pm
by Corey Walker
I always start mine on mag. I never understood choking with the switch off. If you leave it on, it could start on the first pull, or get flooded on the second. Probably not, but it will save some steps. I usually have the switch on, I always open the hood and look at where the timer is and move it with my hand to where it looks good (rod about 11:00 on mine) then choke it through 2 quarter turns. The third quarter turn it usually starts then I can reach in and idle it down. You don’t have to run to the spark lever like when you start on battery. It takes 4 pulls of choke on my ‘21 but it has std cast iron pistons, maybe that’s why. My ‘14 was bored. I rebuilt both magnetos.
If the coils aren’t good it’s my experience it won’t start on mag. I had some coils I dropped off with Ron Patterson at Chickasha but he didn’t have any for sale. I bought a rebuilt set, looked real nice but when I got home it wouldn’t start. I went a put a battery on it and started it but I can’t deal with that. They were rebuilt fine I’m sure, just not set up correctly afterwards. When I got those coils back from Ron I put them in and it fired right up on mag. Still starting on mag 5 years later.
I always switch mine back to mag after I shut it down so when I get ready to drive again I can just walk up to the front of the car, start it and get in. I’ve done it that way for 26 years or so.
Re: Start a T on Magneto
Posted: Thu Dec 16, 2021 6:50 pm
by speedytinc
This begs the question.
How many years/miles or hours run time does one typically get from a properly rebuilt (new caps & points) & tuned set of coils??
Re: Start a T on Magneto
Posted: Thu Dec 16, 2021 9:25 pm
by Scott_Conger
I rebuilt my own coils on the journey to several hundred more over a couple of years.
Having lived in FL for the bulk of my T owning experience and going through multiple summers of high humidity as well as winters with low humidity, I found the nuts would relax or more correctly the wood would move, resulting in loose nuts. Retightening them and checking them annually showed that they stayed in tune throughout the retightening process when checked with a Strobo-spark. Not an endorsement of a tool, just a statement of fact regarding the tool I own.
Now that I am living in 20% humidity in WY with temps ranging from -30F to 100F through the year, the nuts do not seem to loosen, and the coils still do not need adjusting.
So, my 4 cars, with 16 coils, over a 10+ year span, multiple National Tours, many regional tours, and hundreds of hours of pleasure driving, I do not recall ever having to readjust or repair a coil, and I am certain that I have never had a failure. I do not know about the many coils I rebuilt for others, but have yet to receive a complaint.
To answer the inevitable question: I fully anticipated and expected coil failures from the get-go of T ownership, and the nut tightening resulted from casual curiosity and not due to a failure. I no longer anticipate a coil failure and will be very surprised when one happens. With 4 cars and 4 spares, 1,000's of miles of driving and over 10 years of waiting, I no longer lose sleep in anticipation of that day.
With respect to the rash of statements lately of coil points being delicate to the point of not wanting to even touch them, I have found such concerns to be hypothetical in nature and not borne out in actual practice when dealing with 1913-1926 KW style cushion-springed points. Anyone who has adjusted this style coil knows that direct impacts and occasional prying are involved in their adjustment, regardless of the testing device chosen. How anyone could believe that casual handling or shipping portends risk of malfunction is beyond my understanding. Perhaps earlier style coil points are that sensitive...I'm about to find out on a set soon, but am not going to worry about it.
If someone needs something to lose sleep over, well, have at it
Re: Start a T on Magneto
Posted: Fri Dec 17, 2021 10:59 am
by TXGOAT2
The coils' operating environment with the engine mounted coil box is rather severe, with heat and vibration to spare. The coils also have very stiff the hold-down springs pushing down on the wooden cases. Yet they seem to tolerate it well.
Re: Start a T on Magneto
Posted: Fri Dec 17, 2021 4:34 pm
by Scott_Conger
Rainer
rereading your question regarding voltage...starting on MAG, with a good magneto and a not-too-stiff clutch, you will or should get, about 2.0 - 2.5V from the MAG. If your coils are properly adjusted to 1.3A, then you should be able to get it to fire. Starting is not about voltage; it is about amperage