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Discussion Starter #1
A friend has a couple of tractors says they are either 8 or 9ns not sure if it matters too much, Im not sure how to identify them. Neither run but Im only working on one at a time. I do know they have run in the past and dont believe anyone has messed with them since. The one I am currently looking at has a side mounted distributor and negative ground. I replace the battery because it was not holding charge. Im not sure if the fuel system works, I cleaned the sediment bowl but upon failure to start I began using starter fluid to test for spark. Finding none, I concentrated on that. Using a multimeter I tested for ground and power the block is grounded and i have power to the coil. there are two terminals at the coil in excess of the plug wire which goes to the distributor cap. the first is the input and the second has a wire that disappears into the distributor housing i have 6.23 volts from either terminal to the block and at a connector half way to the distributor from the coil. I removed a spark plug which was rusty but looked almost new on the inside. and using the same bare metal spot on the block began to check for spark and found none. I removed the cap and tested for continuity accross the individual plug wires using the inside of the cap. all wires were continous. I took the cap off the dstributor hoping to see the inside but it only gives access to the rotor, theres a plastic cap under the rotor and im not sure how to remove it to look in there. Im hoping the coil is the issue as it would be an easy fix but I want to test and confirm before buying a bunch of parts. If it were mine I would do a full tune up with the coil but I was just asked to get it running and i dont believe in throwing parts at the problem or making those types of decisions for other people. Any how how did i miss anything obvious? and does any one have an idea how to test the coil and distributor assembly.
 

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The rotor should have a clip under it that goes on the shaft before you place the rotor on the shaft. Did you lose that when you removed the rotor? Most folks who do not know it is there lose it the first time they remove the rotor. The plastic dust cover below the rotor should lift sftraight up to reveal the points and condensor but you may need to pruy with a small screwdriver blade to get it started. The wire going into the base of the distributor goes to the points, which are below the plastic dust cover that is under the rotor. Having 6.23 volts at the coil just means that it's getting power, but not whether the points are opening and closing properly or whether the coil itself has the proper resistance through it. Have you measured the resistance from the coil to ground at various positions of the rotor? When the points are open the resistance from the small post on the hot side (non-distributor side) of the coil to ground should be infinite. When the points are closed the resistance should be about 3 ohms.
 

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Oh, and a side mount distributor should be an 8N, or at least it has an 8N engine. Thje 9N's and 2N's all had front mount distributors, as well as the earliest 8N's. They switchesd to the side mount distibutors part way through the 8N production run.
 

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If you have a timing light you could put it on each of the plug wires to check to see if each are getting a spark by turning the engine over. My guess if no spark the points could just need cleaned and regapped.
 

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Discussion Starter #5
thank you I guess i made the usual mistake I didnt see a plastic clip. The rotor fits snugly though so im not sure what it would do. what does it look like, is it like a c-clip. do i need it to get it running? It i will look into prying it off, it was on pretty tight, i assume it will run without the dust cover but i would perfer not to replace it. is there any special way to clean the points, not trying to be a pain, i dont usually get to work with distributors and when I do there is a computer that does the timing. thank you so much.
 

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It is a metal clip. If the rotor is tight then the clip may be wedged up inside the rotor. Here is a link to the parts drawing for the distributor:

Parts drawing for 8N side mount distributor

The clip is the part labelled 28 in the drawing. This drawing doesn't show the plastic dust cover above the points, although I'm pretty sure it has it, and it is listed in the part descriptions on the right side as number 37, but there is no part labelled 37 in the drawing. If it has the dust cover then you cannot run without it because it acts as a spacer to hold the distributor cap at the correct height and if it is missing the cap sits too low and the rotor hits the inside of the cap.

That same distributor design was used on pretty much all 4 cylinder Ford tractors from 1950 through 1964.

Here is the parts drawing for the 641 which used the same distributor design, and this one shows the dust cover:

Parts drawing for distributor for 641

As you can see, a lot of the part numbers are the same for the 8N side mount distributor and the 601 series.
 

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Discussion Starter #7
Cleaned the points with sand paper and gapped to .026. verified it was continous with point closed and not when open. The coil i tested getting 1.2-2 ohms from positive post to negative post. I believe that is a little low but not too far from spec. However, another site told me to test also for secondary resistance from positive terminal and the coil tower and to expect 6 to 15 k ohms however I only got 15.64 so im guessing that is an issue.
i also looked for the clip it was still on the shaft but when removing it I noticed the shaft had some backlash and very minimal side to side play. Not sure if that is in spec. it didnt seem like enough to prevent all th cyclinders from firing but I was not expecting there to be any.
 
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