fordson f

i have a 1927 fordson f, about to try startup after rebuilt engine, manifold,wiring,plugs and buzz box. question is, after talking with several folks nearly all suggest putting a drycell battery in front of coil (with 3way toggle switch breaking line) what type of battery to use). i will build bat box under buzz box. this will be first attempt to start in 50 + yrs.

The original aftermarket battery box held a "hotshot" 6 volt battery - still available from Tractor Supply. The battery box has been reproduced and is available from The Fordson House in Michigan. I have used everything from that to a 12 volt gel cell. The coils don't seem to care too much about the voltage when starting. Crank starting only provides a volt or two from the original mag. so anything is an improvement. Make absolutely certain that you never feed voltage to the mag post from the battery or you run the risk of demagnetizing the flyweel magnets which will cause you to say very bad words. Also, make certain that your timing is correct before you begin to crank. Those old Fordsons have been known to break more than a few arms if they fire before top dead center. Starting them on a battery makes that possibility much greater since the coil will fire at the instant contact is made in the timer whereas if starting on the mag the coil must wait until the mag current hits the magic 1.3 amps which only occure every 22 1/2 degrees of flywheel rotation. You might find an internet video we have uploaded helpful. It is entitled "1926 Fordson tractor compressed air engine break-in". I usually run them on compressed air for 6 - 8 hours after rebuild before I attempt to hand crank them. They crank a lot easier after the bearings and rings seat a little and the oil gets distributed throughout the engine. Not necessary, but kind of neat to see the tractor throwing ice balls out of the exhaust - a real crowd pleaser.

Old, If you have just rebuilt the engine and did all that It should run as designed without having to use a battery. Did you redo the magneto? It might be a little hard to turn over tho so it can't hurt.
If you do however, any battery will do. it doesn't take much. those little gel batteries are nice. about the size of a deck of cards. I put one in the toolbox on one of my Fordsons.