Getting a Farmall A to fire

rpbat

New User
I have an old farmall a I am restoring and I can not get it to fire. I know that the coil, ignition switch, and distibuter work. Also the lights are bypassed. Any help would be appriciated!
 
So you say you know the coil and distributor etc work so explain how you know that.
All the parts can move but still not work as they should.
You need to check your spark at ALL 4 plug wires and the center distributor wire. The spark needs to be a blue/white spark that will jump a 1/4 inch gap of more. Next you need to know for sure you have gas at the carb by pulling the drain plug from the bottom if the carb and let the gas flow for a few minutes. Catch it to look for water and dirt etc.
 
Are you getting battery voltage to your coil? If you are rub the points with some 320 wet or dry, then see if you have fire to your plugs. Hal
 

I tested the kill switch for continuety and conected the coil wire to the coil but disconected it from the distributer and placed the end of the wire 1/8 of an inch next to the negative wire on the distributer and still did not get a spark. Also the coil is new and the tractor was converted to a 12 volt system a couple decades back.
 
From what your saying it sounds like you do not know what you have. Is this a true distributor or a mag??? With out knowing that hard to help you but from what I can figure your saying good chance the points need cleaned or replaced. Bad points equal NO SPARK
 

It is a mag,but the problem is between the kill switch and the coil. I cant figure out what it is though
 
Do you have compression? If you don't pour some oil into the sparkplug holes. That's how I got my JD 420 started after it sat for years stuck (after I got it freed up)
 
If it has a mag to get spark remove the wire from the side of the mag and then spin it over and hold one of the plug wires about a 1/4 inch from the block. A mag does not use battery voltage to make spark
 
From your original post it sounded like it was a battery powered coil ignition (to which I posted a Troubleshooting Procedure), now you say its a Mag?? If its a Mag all a kill switch does is to provide a frame ground connection (via a kill switch) when turned OFF/Stop but its open (NOT to ground) when On/Run. As long as the mag (if kill switch terminal equipped) isn't grounded it can fire

Most common problem on Mags is the points are burned pitted or corroded which a good clean/buff/polish or use of a points file may cure

John T
 

I checked for continuety between both battery temernals with the baterry disconected and I did have continuety. Does this mean I have a short circut?
 
Just take the ground off the mag and try it. The battery has nothing to do with ignition. It is likely a problem in the mag and not that ground wire but if you remove it and it fires that wire is grounded somewhere in which case just run a whole new wire.
 

I got the wire that runs from the coil to the mag and disconected it from the mag, then I placed the end that conects to the mag 1/8 inch away from a grounded bolt and I did not get a spark.
 

I think that it maybe a distributer and not a mag because it was converted to 12 volt system. How can I tell if this is a mag or a distributer.
 
This is with the engine cranking right ? The mag is the ignition the battery and the mag should have no electrical connection. You don't run any power to the mag .
 

Now im thinking I have a distrubuter because there is a 12 volt coil that sits above the distributer.
 
You have a distributor. Refer to John T's advice. On a normal Farmall A the mag is a self contained ignition . When yours was converted to twelve volts someone probably put a distributor on it. SEE JOHN T .
 


I refered to John T's advice

The first step was

"To see if it happens to be a cap n rotor problem and to see if at least the coil is firing, remove the coil wire from the distributor (leave coil end intact) and place its bare end to within 1/8 inch from tractor iron, turn her on n crank her over, and see if she jumps that gap with a good visible blue spark?????? If so but the plug wire ends (from wire end to 1/8 inch to frame) or the plugs themselves don’t fire, its a cap n rotor or plug wire problem. If the coil wire isnt even sparking, see below."

I could not get a spark between the coil wire and tractor iron.
 
How come I have to type my name every time. Okay anyway he is referring to the secondary or "spark plug thickness wires " when he is telling you to do that test . Check a wiring diagram and make sure the points { smaller guage] wire goes to the negative side of the coil. If I'm thinking backwards John or Old will yell at me. I did not read Johns Troubleshooting guide.
 
I never saw an "A" with a distributor. Was there a conversion kit for these? Unless some one is trying to use the points in the mag for a conventional ignition system which I don't think will work that way.
 
No he said he had an external coil. It could be possible to use the action of the stock points in the mag for a battery coil conversion . Once you have a round coil not inside the magneto you will need wiring for a battery coil ignition and power to the coil where in the stock mag putting power to it will cause big trouble. A mag makes AC and a battery coil ignition fires on the collapse of the coil all DC.
 
The tractor was originally had a 6 volt system, my grandpa had the tractor converted to a 12 volt system many years ago. That was probably 30 or 40 years ago. Everything on the tractor was working when it was parked but it sat for almost 10 years.
 
If everything worked before and you did not just rewire this clean the points and it should fire right up. Sorry I can't be of more help but ---bedtime. Did you at least change the spark plugs or pull them and look at them. I never heard of a coil going bad in storage.What happened when you pulled the wire as in John T's instructions ? Did you get spark then? Got point gap ? Mouse chewed anything?
 

Well I have a brand new coil but it will not fire, what triggers the coil to send electricity to the distributor?
 
The coil has power the points trigger the coil . Use John T's page he posted the link to I just read it and have read it before. It should get you to where you want to go.
 
The points are getting power from the negative coil terminal. If Johns info is not helping you can google up some battery coil ignition diagrams. If the tractor ran before not much should need to be changing as far as the way it is wired.
 

I took his advice and I am not getting a spark from the coil, I am unsure what to do now, I know the coil is good because it was just replaced.
 
If you have a mag the battery and the mag is never ever hooked to each other and if it is then you fry the coil in the mag the moment you hook things up. Still sounds like your lost and do not know what you have a mag or a distributor???????????
 
Easiest way to get a Farmalittle to fire is to pour a gallon or so of gasoline (regular is OK) over the top of it and toss a lit match in.... (SORRY, I just couldn't help my rotten self....)
 
If you still have a postitive ground system then you need to reverse [or just hook up ] the leads to the coil as such: wire from switch to negative on coil----- wire from + on coil to distributor. If it is positive ground make sure this is correct. Negative ground then reverse of what I just typed.Did not think last night you may have positive ground.
You can also try bypassing switch : leave it hooked up but add a wire to bypass directly to coil from battery.
 
(quoted from post at 19:03:38 03/31/13)
I took his advice and I am not getting a spark from the coil, I am unsure what to do now, I know the coil is good because it was just replaced.


You are in the dark here. Heres what to do.Enlist the physical help of a compatent tractor mech.
 
(quoted from post at 05:29:09 04/01/13) If you still have a postitive ground system then you need to reverse [or just hook up ] the leads to the coil as such: wire from switch to negative on coil----- wire from + on coil to distributor. If it is positive ground make sure this is correct. Negative ground then reverse of what I just typed.Did not think last night you may have positive ground.
You can also try bypassing switch : leave it hooked up but add a wire to bypass directly to coil from battery.

I believe there is something keeping me from getting voltage to the coil, the kill switch is good. Any ideas?
 
Do you have a 12 volt test light that you can use to see if you have power to the coil? Which battery post' + or - is grounded to the tractor frame? Do you have the ability to connect a 'jumper' wire( with alligator clips) from the hot battery post to the battery side of the coil? If so that will bypass your 'kill switch', then spin it over with the coil wire out of the dist. cap and 1/8 to 1/4" from the tractor frame. Do you see a spark?
Take the distributor cap off and drag a business card or some brown paper through the points when they are closed to remove some oxidation. Be aware of the order of the spark plug wires in the distributor cap, they have to be in a certain order. When you get the dist. cap off there is a 'rotor button' that will pull off and a protective cap under it that covers the points and condenser, it pulls off easily. Know that your test light will only show power to the coil when the points are open.

Try to be methodical and logical. Study John T's guide and identify all components before you start, to the extent possible. We have a Super A and it has a battery/coil ignition
 
You can't make statements like you believe you have no power. Get a test light or meter and start testing stuff. It sounds to me like you need a mechanical friend to come over and you just buy the beer.If you have postitve ground you may have hooked up the coil in reverse. That is the only thing you changed since it was running so check your coil connections. Coil connection reverse for pos vs neg ground systems. Check that if coil is correect jump past switch and test coil lead. If no spark go to inside distributor and clean contacts using clean bus card and lacquer thinner. Don't leave small bits of paper in points.
 
You do realize if you have a positive ground system you need to get the "hot lead"to the coil /switch from the negative terminal.
 

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