Update to dang it! Battery backwards

Charged my new 6 volt batt last night. Hooked it up correctly this time
and the engine rolls over just fine. Now I have no spark from the
wire coming out of the coil to the dist. I had fire there yesterday.
Did I fry it? I don't how to check a coil. I did put my volt meter to
the two terminals set to check ohms and the needle went way
over. Don't know if that means a good coil or not. Should I look
somewhere else for my problem or just replace the coil and
points and cond while Im at it. I am so dumb and cost my self a
lot of money and extra work sometimes. Oh well going out for
some Mexican food with the wive now to La Hacienda our
favorite place. Maybe that will settle me down a little.

Putting the battery in backwards did no harm to any electrical component. If the engine had started, it still might have been OK. Do not fret.
The coil points condenser and ignition switch can (and have been run with reverse polarity.
More to come. Jim

To fix the ignition system:
Lets set the meter to do what is needed. On the front there will be a setting for OHMS. Turn the switch to Ohms RX1. Now find a small wheel (like a volume control) that says Ohms adjust. now place the two meter leads together so they touch firmly. The needle should go all the way across to Zero. If it is not on Zero, adjust the control to make it so. when they are apart, the leads have infinite resistance, when together no resistance.
With the ignition switch off, the coil can be measured from small terminal to small terminal. it should read almost zero, Maybe up to 3 ohms. If it reads more like 100 Ohms, or no movement, the coil may be bad.
Now set the meter to 20 volts DC (or more than 6 less than 200. Turn on the ignition switch (do not start it). test from a shiny metal bolt head on the tractor engine, to the small coil terminal that leads to the ignition switch. The reading should be about 6.3 volts or so. If not the ignition switch or wires to the coil are not providing voltage, fix the source by back tracking to find the place the voltage stops.
Now check from that shiny bolt head on the engine to the coil terminal attached to the distributor side terminal. It should read nothing or less than 1.2 volt, if the points in the distributor are closed. Shut off the ignition.
Open the cap, and see if the points are closed. if there was 6+ volts when you measured the last coil terminal the points may be open. If they are closed, and voltage was seen at the coil terminal attached to the distributor, the points are either disconnected, or they have a particle of dirt between them. Clean them with a folded dollar bill by opening them and putting the bill between and closing the points on the bill and pulling it out.
Now put the dollar back between the points and leave it for the next test. Turn the ignition back on and check the coil to dist. terminal again, as in the prior step.
Now there should be voltage there. Pull out the dollar and there should not be voltage. The points ground the coil to make it work.
If these check out, put the rotor and cap back on and start it. If no success, let us know, and we will go farther. Jim

hey, don't fret over a little mistake, it doesn't get any better. i am 69 years old.

proper electric hook up on 6 v, + always faces ground. so coming from battery, + goes to - side of coil and coming from coil + faces distributor or ground.

Have you fire coming to coil? if so remove lead wire from coil to distributor at the distributor, replace distributor high voltage wire with spark plug wire and connect to an extra spark plug and ground the plug. ignition switch on and strike loose end of lead wire to ground, if plug fires, coil is good.

Unless it has electronic ignition you did not hurt the ignition system any. But what could be wrong is very simple like the points needing to be cleaned or replaced. Pull the cap/rotor/dust cover and turn the ignition on and open and close the points by hand. You should both hear and see a spark. No spark points need to be cleaned and or replaced.

Good Mexican food is always yummy. Forget the multi-tester. Save it for trouble shooting your submersible pump. Open the points with your screwdriver and see if it throws a spark out the high tension lead. You can unhook the wire that goes to the distributor, use a jumper wire to ground that side to the frame. When you unhook the wire you should have fire. That would be the most elementary way to test the coil only.