I have a 1922 Ford touring and when I keep it on battery it runs much better but when I switch it over to magneto it runs rough and backfires and doesn't move fast......someone said where the wire goes to the magneto on top of the transmission that you need to remove that and clean it off and use a emery board for the brushes? I am new to a model t so please any help will be appreciated......and any quick tips on driving it better and safer.
Check this thread for some ideas on your mag problem.
Also, a symptom of improperly adjusted coils if the they may work better on bat them mag. Are your coil adjusted correctly?
I think Jim may be correct. I had a weak mag and if the coils were adjusted to 1.2 it would run on battery. When switched to mag, it would hardly run. I had to detune the coils to .8 before the car would run very well on mag. It also ran well on battery at .8. However, the power was not there.
If you have a mag post outside oil line, check to see if the inner magneto post is shorting out against the oil fitting that screws into the side. Sometimes the fitting is too long and if screwed in tightly, can seat against the inner mag post contact rod. Even if the end of the fitting does not touch the post, it could be just close enough to cause an arc. Mine was long enough to touch the post, so that and I had to remove it and grind off about 1/8" from the end, not only to prevent a short, but also to increase the access opening of the end of the fitting so that the oil splash could get to the mag post oil line opening so it would do some good. Jim Patrick
The first thing to do Anthony would be to go thru your entire wiring harness and correct any problems with loose, frayed or shorting wires.
Second thing to do - have your ignition switch rebuilt by a competent T-guy.
Third thing is to rebuild your coilbox using the plastic rewooding kit (seriously). You can do this yourself. The only special too needed is a long(er) handled rivet setter. Unless you're bigger than the average friendly bear the regular sized setter just won't do!
The fourth thing to check is the voltage output from the magneto to see if it's sufficient for proper coil operation. If the voltage is too low the coils will not work properly. The correct method to measure this has been posted repeatedly over the years.
Fifth step is to check the condition of your timer. There are many choices of timers to use, both vintage (from online auctions) and new (from dealers). Some may be better than others - it's up to you to decide which is best. An oft-ignored facet is whether your timer cover plate is correctly centered about the camshaft.
Final thing to do would be to have your coils rebuilt by a competent T-guy. After that, hang on and enjoy the ride !!
As you can see, unfortunately, there's no simple answer or fix for your problem Anthony. Everything has to be in good working order, and special attention must be given to ignition coil contact setup.