8n ford wont start

I have an 8n ford side mount distributor that won't start. I have a spare plug connected to a plug wire and get fire. I have tried starter fluid into the breather and it doesn't hit. I have omhed the switch and it never zeros out when connected inline. If i test it off the tractor i can get a zero reading. I connected the two wires together to by pass a switch. I also omhed the ceramic piece by the switch and it zeros out so it looks to be good. I am wondering if the actual plugs are bad but they are siezed in so I am soaking them overnight and plan to replace them. The system was converted to 12 volt several years ago but it looks like the old coil is still on there. I was told it may not be a strong or consistant spark even though i get a spark at the plug. Any suggestions?

As a new 8n owner myself my knowledge on starting problems is limited, however when I first got my tractor, it was doing the same thing getting fuel,
firing etc. I did some research on this site and one of the forum answers was that the older tractors have to have a very good battery to help the
ignition to spark. The battery I had was ok, it started my step dads Nissan, but it wasn't until I got tired of messing around with it and bought a
770 CCA battery that I got it to start. I don't know if this what is going on with yours but it maybe a place to start.

Since you have a side mount pull the center wire off the distributor cap and check spark there. You need a blue white spark that will jump a 1/4 inch gap or more. If you have a good spark there pull the carb drain plug and make sure you have a good steady flow of gas form it for say 3 minutes. Catch the gas to look for water/dirt etc. If you have good flow pull the air intake tube off and hold you hand over the carb air intake and make sure you get a good suction. You should fell a good suction there and also get gas on you hand. If low suction or no gas you have a vacuum problem or a carb problem

I will try those suggestions in the morning. The battery cranks it over very fast. Do you know how to check a coil? I bought a new one but if I don't need it I will take it back,,

The round can coils are pretty much bullet proof. That said if you still want to test it that is easy also. Hook one side of the coil to one post of the battery and the other to the other post. Hook and unhook it fast and you should get a spark from the center wire each time you unhook it. If you make the mistake of holding the center wire in your hand you will know real fast it is is working or not because you will jump 10 feet. LOL

" I have a spare plug connected to a plug wire and get fire."

Unless you opened the gap on that old plug to 1/4" & saw a spark, you haven't checked for spark correctly. Re-check the spark & tell us what you found.

" I also omhed the ceramic piece by the switch"

That's called a resistor. If you have a resistor on a round coil, chances are you have a 6v coil. Check it to confirm.

" Do you know how to check a coil?"

Coil problems are difficult to diagnose. For starters, round coils are pretty robust & square coils aren’t (because of the difference in insulation used), but neither one will hold up to a poorly done 12v conversion that allows too much current to the coil or leaving the key on (see tip # 38). Too much current creates heat which melts the insulation. Insufficient resistance in a 12v conversion will do the same thing. Rarely do coils just “go bad.”

As others have said, there are a few ways to see if a coil is bad, but it’s not possible to determine if a coil is good w/o some expensive testing equipment. If you detect a dead short or high resistance in the coil w/ an ohm meter, it’s bad. If it’s cracked, it’s bad. If a sidemount coil w/ battery voltage to the primary will not jump a ¼” gap from the secondary wire to the block, it’s bad. But, here is the hard part: even if you do not detect a short, even if it will produce a spark, even if it’s not cracked, that doesn’t mean the coil will work when it’s hot & under a load. So, it’s a process of elimination. If the tractor starts & runs fine for 30 minutes or an hour then cuts off & refuses to re-start, and you checked for spark at the plugs & it had no spark at all, AND you have the correct voltage at the coil that’s a good sign that you have a bad coil. Let it cool off, restart it & if you have a good spark, odds are it’s a bad coil. But, even then, you might end up w/ a spare coil on the shelf!

Bottom line.......coils do go bad, but I'll venture a guess that 75% of new N coils sold today are sold to folks who do not understand how to diagnose a poor spark problem or how a coil works. So, for those who don’t know any better, in a no spark situation the first suspect is usually the coil……and, more often than not, it isn’t the problem.

Or as one regular around here humorously suggested: "Well, it is like this...I don't know or really understand what that black thing does & I am suspicious of the unknown, so I think the problem is the black thing."
75 Tips

(quoted from post at 03:22:59 05/16/15) I have an 8n ford side mount distributor that won't start. I have a spare plug connected to a plug wire and get fire. I have tried starter fluid into the breather and it doesn't hit. I have omhed the switch and it never zeros out when connected inline. If i test it off the tractor i can get a zero reading. I connected the two wires together to by pass a switch. I also omhed the ceramic piece by the switch and it zeros out so it looks to be good. I am wondering if the actual plugs are bad but they are siezed in so I am soaking them overnight and plan to replace them. The system was converted to 12 volt several years ago but it looks like the old coil is still on there. I was told it may not be a strong or consistant spark even though i get a spark at the plug. Any suggestions?

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You should also test your wires you may or may not have solid core wires you WILL need to know the spec on the wires measure the length of each wires in inches measure the ohms divide ohms by the inches wire is long. This will give you ohms per inch. times the ohms per inch by 12 to get ohms per foot. If it less than the spec on the wire it is really good. Example the spec may say 30k to 40K note: 28K would be even better. You just don't want to see it over the spec for the wire in the example over 40K would be no good. IF YOU HAVE SOLID CORE WIRES YOU WOULD HAVE VERY LITTLE MEASUREABLE RESISTANCE.
I HAVE ADDED SOME IGNITION TESTING AS WELL AS COIL TESTING AND PLUG TESTING VIDIEOS.PARTICULARLY CHECK THAT YOU DONT HAVE A PLUG THAT IS LEAKING SPARK TO GROUND. IN ADDITION I WOULD CHECK YOUR VALVE LASH AND LOOK FOR A STUCK VALVE OR BROKEN VALVE SPRING.
YOU CAN ALSO CHECK YOUR COMPRESSION IF YOU DONT HAVE A COMPRESSION TESTER IF IT BLOWS YOUR HAT OFF ITS PROBABLY GOOD.


There are some tests you can do that MAY HELP FIND the problem for you

https://www.youtube.com/watch?v=bl0Z6kbyI0c

https://www.youtube.com/watch?v=e66tA43wsNo

https://www.youtube.com/watch?

This fellow is a little long winded so skip to around 7 minutes if you can stand it!
v=h8vSwfnX3Xc&list=PLskh86IwPs9AeFOBgzy2oSzzvzXG1D0c4

https://www.youtube.com/watch?v=-vdC2rwclGo

http://www.yesterdaystractors.com/articles/artint131.htm

If it help YOU great if not maybe it will help some one else.
GOOD LUCK BYRON