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9n sat for a couple of weeks and now won't start

2883 Views 71 Replies 10 Participants Last post by  Vigo
Guys, hi, and thanks in advance for any advice.

So, I am a real noob when it comes to tractors and the internal combustion engine, in general.

I needed something to haul logs from the woods, so a neighbor sold me a 1945ish Ford 9n 6 volt

It ran well enough when I was testing her out. Drove it home. The carb was leaking, I knew this, but was keen to get stuck in and learn a thing or 2. I was busy with house repair, and let the tractor sit for a couple of weeks. Yesterday I took the carb off, gave it a good clean. The float needle seemed a little sticky. I have a new one on order, but reseated it as best I could and so far, the leaking is drastically reduced/addressed

However, when I went to run her, she just wouldn't bite. Starter works, belt drives the shaft, but no spark or explosion, best as I can determine. I put in new 437, and then 216 plugs, for less resistance and a smaller gap. When I hit the ignition with the new plugs, I hear a loud electrical whine the first time, but no crank. It cranks after that first try however.

On 2 occasions, once today and once yesterday it almost coughed into life, very briefly.

I drained the carb, took the plugs out, added some oil to the plug holes, I can feel compressed air coming out of the holes when I turn the ignition on. I even tried warming the plugs with a lighter.

Battery reads at 6.3, so seems fine. It was a new one too, I am told.

So, where do I go from here? What is next on the list of things to try?

I have already looked over one or two threads related to engine flooding and hard starting and tried all I could find from those.

Thanks again guys. Really hoping to get her operational soon. I have many logs to haul!

Benson
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Are these screens replaceable or do I need a whole new valve?
There should be both a vertical coarse screen and a horizontal fine screen at the top of the glass bowl. The whole new valve isn’t expensive. $17 at just8Ns. I’ve bought them at Tractor Supply, too and they work fine.

the vertical copper tube is your reserve fuel system. Just cracking the valve doesn’t give access to the last two gallons. Opening it all the way accesses those final two gallons to remind you to fill up.
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OK, so I've ordered a complete tune up kit. This will come with the new fuel valve I need and condenser, points etc. I have a new coil already. I'm just gonna take off the hood for now, clean the tank and plugs and wait for the parts.

what an intro to the world of old tractors!

Learning a lot I guess. Can't put a price on that. :p
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OK, what the heck?? I just took the hood off to make room for putting in new plug cables and coil etc. Battery disconnected in advance, no key in the ignition. Did this happen during my back fire event??



I find the coil completely melted!

Automotive tire Wood Road surface Floor Helmet
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OK, what the heck?? I just took the hood off to make room for putting in new plug cables and coil etc. Battery disconnected in advance, no key in the ignition. Did this happen during my back fire event??



I find the coil completely melted!

View attachment 2562238
As another poster pointed out earlier, there are about a zillion little wires in the coil. From the looks of your coil it’s a real old timer. If you know your plastics (retired chemist here) the originals usually had “Ford” in script on top but not always. They used a Bakelite plastic that is dull rather than shiny and sometimes they are slightly lighter than pure black. The newer ones are a very shiny black engineering plastic.

I would get it into the trash ASAP. I have no clue what was in the tar filling that has oozed out.

Why it failed:

Old age

Did someone convert your tractor to 12 volts? It’s easy to tell - the negative terminal will be grounded versus the positive terminal with 6 volts. If the conversion is done there should be an aftermarket resistor in the wiring ahead of the coil. This protects the coil, although I’ve never seen as spectacular a meltdown as yours. Usually the extra voltage fries the points quickly before damage to the coil.

Keep us posted. There’s nothing wrong with a 12 volt conversion if done right. You can even buy an aftermarket 12 volt coil and not bother with the resistor.

don’t be afraid to take the two bolts out and take the whole distributor off the tractor. It’s much easier to work on that way. It has a key on the shaft that will only allow you to reinstall it one way. Just hold it in place and turn it until the key on the shaft clicks into place. Then put the bolts back in.
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As another poster pointed out earlier, there are about a zillion little wires in the coil. From the looks of your coil it’s a real old timer. If you know your plastics (retired chemist here) the originals usually had “Ford” in script on top but not always. They used a Bakelite plastic that is dull rather than shiny and sometimes they are slightly lighter than pure black. The newer ones are a very shiny black engineering plastic.

I would get it into the trash ASAP. I have no clue what was in the tar filling that has oozed out.

Why it failed:

Old age

Did someone convert your tractor to 12 volts? It’s easy to tell - the negative terminal will be grounded versus the positive terminal with 6 volts. If the conversion is done there should be an aftermarket resistor in the wiring ahead of the coil. This protects the coil, although I’ve never seen as spectacular a meltdown as yours. Usually the extra voltage fries the points quickly before damage to the coil.

Keep us posted. There’s nothing wrong with a 12 volt conversion if done right. You can even buy an aftermarket 12 volt coil and not bother with the resistor.

don’t be afraid to take the two bolts out and take the whole distributor off the tractor. It’s much easier to work on that way. It has a key on the shaft that will only allow you to reinstall it one way. Just hold it in place and turn it until the key on the shaft clicks into place. Then put the bolts back in.
No, still 6v , positive ground. Ye, I took the hood off to get at the distributor and plug wires.

The gas tank bolts are in poor shape, and I don't think I can get 'em off without cutting them.

Installing new plug wires looks like it might be a pain with the built in conduit pipe
So. I'm reading that bad plug wires can cause coil burnout. Anyone experienced this?
Lots of things can cause the coil to overheat. A direct short to ground in any spot inside the coil itself or along any of the spark plug wires are just some of the possibilities.
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I just did the plug wires and a new harness on my 9N during a restoration. I also have the conduit. I just taped the new wire to the old end to end and pulled them through. Just make sure to use plenty of tape and push and pull the wires.

Why are you trying to remove the fuel tank?


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I just did the plug wires and a new harness on my 9N during a restoration. I also have the conduit. I just taped the new wire to the old end to end and pulled them through. Just make sure to use plenty of tape and push and pull the wires.

Why are you trying to remove the fuel tank?


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If you’re going to this much trouble some people take the opportunity to epoxy line the gas tank. Google POR-15 and there are competitors products available, too.
Most likely reason for coil to overheat is simply key was left on while the contact points in the distributor happened to be sitting in a closed position.
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Most likely reason for coil to overheat is simply key was left on while the contact points in the distributor happened to be sitting in a closed position.
would the distributor also be impacted under such a scenario?
The points themselves may have overheated and need cleaned or replaced. The heat will develop wherever the resistance is in the circuit. If the points are making a good clean connection with low resistance, the coil will be the majority of resistance in the circuit and so will develop the majority of the heat. If the points themselves were making a poor connection they might burn up before the coil does.
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