8N cranks, won't start

Need some help. A friend has become limited in his mobility and asked for my help getting his 1952 Ford 8N started. The tractor sat for a couple of years. He picked up a new battery and I put it in for him. He said that he was told the tractor had been converted to 12 volt. When I went to install the new battery I was surprised to find that it had been wired to positive ground. Now, I have to be honest, at this point I was questioning whether I had noted the position of the old battery correctly. I knew that positive ground had been used sometimes because I had a few British sports cars as a kid. Anyway, I know nothing about tractors. We installed new battery and would crank but not start. Found ignition switch to test faulty, and just hot wired it. At this point using a test light I found we had a steady light at the distributor side.( side mounted distributor).We got a tune up kit, installed new points,condenser,rotor,cap and plugs. Started bright up , yeah! over the course of the next few days we started it maybe half a dozen times. Installed a new on/off switch and moved it out to the road to be For Sale. A few days later we tried to start again, it coughed a couple of times and then nothing. We thought we had flooded it so waited till another time. Another couple of days later, tried to start, still turned over, but would not even cough. Checked with light again and found power to one side of coil , but not other and no power at distributor side. Installed new coil, same problem. Installed another new condenser, same problem. It seems as though this tractor had a partial 12 volt conversion. The wiring is stil as original with an external voltage regulator and what appears to be a generator, not an alternator. There is no ballast resistor in line the wires ran to a terminal block as original. I'm stumped and really know nothing about these tractors, other than it is an awesome piece of machinery when it runs. Thanks for any help.

It's got a side coil; it never had a resistor & does not need one w/ a 12 volt coil.

I can't ID the generator from the pic, so it could be a rare 12v conversion w/ a generator.

But don't worry about that right now.

Confirm that you have voltage to the coil. Battery voltage, points open. About half that if the points are closed.

Do you have battery voltage across the points when they are open? (with the points open, put one probe on one side of the points & the other probe on the opposite side of the points) Verify the gap on the points at .025. Then, dress the points by running a piece of card stock or brown paper bag through them. New points sometimes have an anti-corrosive dielectric coating on them & old points can corrode or pick up grease from a dirty feeler gauge or excessive cam lubricant. (I always spray my feeler gauge blade off w/ contact cleaner.) Make sure you have voltage across the points, as in past the insulator on the side of the distributor. That is a very common failure point on sidemounts, along w/ the attached copper strip. It's hard to find a short there because it is usually an intermittent . So 'wiggle' the insulator & the copper strip a bit when you are doing your checking. If you find the short there, the Master Parts catalog lists everything you need on page 154. You can make the strip and you could also make the insulators as well. But, somethings are just easier & in the long run cheaper to buy. Get the strip, 12209, screw 350032-S, 12233 bushing & 12234 insulator & just replace it all.

If you just replaced the rotor & lost spark, put the old one back in. Insure that the rotor fits firmly on the shaft & that the little clip is there. Make sure the distributor cap is not cracked, doesn?t have gouges in it from the rotor or brass shavings & doesn't have carbon tracks. Check continuity on the secondary coil wire. Make sure it is firmly seated in both the cap & the coil. In fact, replace it temporarily w/ a plug wire. Next, remove the secondary coil wire from the center of the distributor cap, turn the key on & crank the engine while holding the end of the wire 1/4" from a rust & paint free spot on the engine. You should see & hear a nice blue/white spark. If not, you have a bad coil or condenser. Just put the old condenser back in to eliminate that as a possibility.

Post back w/ results; I'll be interested in what the problem was.
75 Tips

Bruce, thanks for the reply. Those are all good points. I've been gone all day sorry I didn't get back to you sooner. The tractor is about half an hour from me and they are predicting rain for the next few days, so it will be a while before I get out there. But, you can be assured I will let you know how we make out. Thanks again... Wayne

Bruce, just want to let you know, we got the tractor started. It was the insulator/ copper strip on side of distributor. AS you said it must have had a tiny crack, we wiggled it and she started right up. So, we'll order the parts, mystery solved. Still not sure about the 12 volt generator conversion, but the next owner can figure that out. Thanks for your help...Wayne