Can anybody tell me why my T wont crank start on mag, but it crankstarts really good on bat? It also runs really good on mag, maybe its not important to start on mag, or not supposed to, I dont know.
My grandmother always started her '15 Touring on MAG. She never owned a battery for the car. It was made into a tractor around 1932 and still never had a battery.
If you have good coils, good magneto, and good technique it ought to start just fine.
If the car runs OK on the magneto after starting on battery you should be able to hand crank start the engine on magneto. Try this (do it with the engine warmed up first as it will delete the mixture adjustments and the initial charging the cylinders with fuel/air mixture that are required when starting a dead cold engine): Set the emergency brake, place the key switch in the magneto position, advance the spark lever 3-4 notches on the steering column quadrant and give the crank handle a sharp quick pull from 7pm to 11pm.
The Model T ignition timing requires that you advance the spark lever a few notches for easier starting on the magneto. I know this seems counter intuitive because we are always told to retard the spark lever for starting, but it is different when starting on magneto and you need the spark advance to make it much easier to start. Remember NEVER advance the spark like this when starting on battery
Let us know the results of this test? If this doesn't help you can contact me directly and I will be glad to help you with checking some of the additional factors that can cause trouble with magneto starting.
Ron the Coilman
Mr. Lawrence, that is one of Life's Great Mysteries, along with a Woman's Mind. We hand cranked T's forever on Mag, the batteries were always dead or weak. Mama's Sister's "Jitney", a very early T, looked like the ones with the Mother in Law seat except it didn't have that seat, did not have a starter or electrical, it was all brass with a carbide generator, and second handed to boot. My Grand Daddy had bought it for her to go to School, about a 20 mile drive one way. One of us would have to crank it for her in the AM (on Mag) then some boy who was dragging his wing around her would crank it up in the PM so she could come home, don't know what she would have done if it had quit on her on the way home. That car went into the Scrap Drive during the War, we all cried a little when they loaded it. My '25 ran better on Mag than Battery, but it quit running on Mag altogether yesterday, and I have not really looked for the problem as yet. It ran as good as any of them on Mag, but I never was able to get it started on Mag, will try Ron's technique when and if I get it up and going again.
....give the crank handle a sharp quick pull from 7pm to 11pm.
I had to do it in an emergency, dead battery, car ahead of me couldn't decide where he was going & my left & right foot kept going up & down until I stalled, in the middle of a busy intersection. I'd never tried starting on Mag, I had the instruction manual in the car, set the spark & throttle (as Ron stated) put the key on Mag & she started on the first pull, I was on my way to Pep Boys for a new battery.
How loose is the engine? You need a quick pull on the crank, and if it is too tight you can't pull it quick enough. You also need a good magneto, you need about 4-6 volts at idle and if the mag is weak, you need to get it going faster to have enough spark to run on mag. I have started one of mine on mag. It had been driven earlier that day but the battery was low. It started right up with one pull of the crank. If you have a high compression head, you might also have a problem with being able to pull the crank fast enough because of increased compression. Also a combination of high compression, and too tight bands or clutch. Jack up the rear wheel and it will relieve to drag from the transmission.
Ive tried a few things today to start it on mag, will try again tomorrow. Im thinking my coils need to be set up right. My engine is pretty loose, I do know that I have at least 6 volts at idle. Well see what happens with some good coils. Model T people sure are helpful!!
I had started mine on mag one time but it was hard to spin it fast enough.
Then last sunday I had a visit from a guy that had model T's all his life and I showed him mine. After I started it and warmed it up a while, I started it on bat with the crank (because its cold here still and the engine turns hard in the 30's). After I shut it off he asked if it would start on mag so I switched it on and turned the crank just past TDC and the darn thing started! I did not expect it to start so easy on mag and this was only the second time I had done it by hand. I also used the starter one time when I killed it and forgot to switch back to bat before I stepped on the button. I also had the spark pulled down about 2 or 3 notches which for my car is where it starts best either way.
Warm yours up and try it and if it runs good on mag I bet it will start.
Hi Brian. My method of starting on mag is to have the spark lever 4 or 5 notches down, and have the throttle open about 5 notches. A quick pull from 9 to 12 is what I use....then I quickly back off the throttle and away I go. Mine starts easily on mag hot, and not as easily cold. As stated, you have to give it a good sharp spin, as the coils won't already be buzzing, as on battery.
Have fun, and keep your thumb on the same side of the crank as your fingers!!
I did it! It dtarted on mag, but later in the day when the car was really warmed up, I couldn't do it again. Sure was a good feeling though, when it did start on mag. Ive still got some experimenting to do, so we'll seel what happens. These model T's are are addictive, I really want to get this thing to run the way it was designed to. (maybe this will drive me mad in the long run) It runs so good, that I know that Im close to gettin it dialed in. Any suggestions welcome
My '18 would not start cold on mag, even though it ran and drove fine, until I recharged the magnets. It starts in two flops now.