8N Side-mount insulation points.

[Baumanm]

Two questions:
1.) I have an 8N side-mount that I rebuilt recently. No spark beyond the cap. Points, cap, rotor, condenser and coil are all new. Ran the typical tests recommended here, but still cant get spark. On a suggestion from another site, I eliminated the post on the side of the distributor and ran a wire through a grommet and wired straight to the points. I checked the wire and the grommet and everything is intact, so it shouldnt be a grounding point. Is there anywhere else there is supposed to be insulation? Between points and breaker plate for example?
2.) When I have tried to start this tractor it cranks slow. My old diesel cranks faster in the dead of winter than this thing does on a 90 degree day. Had the starter load tested and it checked out. Moved the battery ground to the frame. Cleaned the terminal nails on the starter and where it contacts the frame. Good 6-volt battery. Im at a loss.

 

[JMOR]

(quoted from post at 12:50:35 12/06/21) Two questions:
1.) I have an 8N side-mount that I rebuilt recently. No spark beyond the cap. Points, cap, rotor, condenser and coil are all new. Ran the typical tests recommended here, but still cant get spark. On a suggestion from another site, I eliminated the post on the side of the distributor and ran a wire through a grommet and wired straight to the points. I checked the wire and the grommet and everything is intact, so it shouldnt be a grounding point. Is there anywhere else there is supposed to be insulation? Between points and breaker plate for example?
2.) When I have tried to start this tractor it cranks slow. My old diesel cranks faster in the dead of winter than this thing does on a 90 degree day. Had the starter load tested and it checked out. Moved the battery ground to the frame. Cleaned the terminal nails on the starter and where it contacts the frame. Good 6-volt battery. Im at a loss.

ou say, "no spark beyond the cap".. Does that mean you have a spark to the cap? From the coil?

 

[Jim.ME]

"No spark beyond the cap". Does that mean you have spark from the coil wire if you remove it from the cap and hold it about 1/4" from the block? If so, is the clip on the distributor shaft under the rotor? If you had the distributor out as part of the rebuild, did you static time it so you know it is lined up to fire on #1 TDC compression?

If the cranking is as slow as you describe, there is still something wrong. Immediately after cranking feel the battery cable connections for heat. If one is warmer than the others there is resistance, there. What size are the cables? 0 or 2/0 is best. Do you have a voltmeter? What is the voltage across the battery terminals while cranking? What is the voltage on the battery cable of the starter while cranking?

 

[Baumanm]

I used a bulb tester (didnt have a multimeter with me) to determine that with the key on I had power to the coil and from the coil to the points. I did unplug the coil wire at the cap and try to ground it to the bloc, but didnt get anything. With that being said I now remember that I tried doing this on a painted surface. Not a good idea. I did take the cap off and try starting it to see if there was a spark at the points, but something is telling me that might be a useless test. The clip that is supposed to be under the rotor is there and I static timed it before I put the distributor back in.

 

[Baumanm]

Ill have to check the cables when I get a chance and recheck everything with a multi tester. Unfortunately the tractor is 90 miles from me. Going to have to convince the wife to let me put something else in the garage.

 

[Jim.ME]

(quoted from post at 16:40:03 12/06/21) Ill have to check the cables when I get a chance and recheck everything with a multi tester. Unfortunately the tractor is 90 miles from me. Going to have to convince the wife to let me put something else in the garage.

This may be considered semantics, but it can be critical in trying to help you diagnose your problems. It sounds like you have primary power (primary power is via the wire from the switch) through the coil to the distributor. Spark comes from the big post of the coil through the coil wire to the distributor cap. If you didn't see any spark, I would say you don't know for sure that you have any spark, much less beyond anywhere. I have seen a good coil give a spark even to painted surfaces.

You say the battery is good. Did you have it load tested? Even new batteries can be bad.

If you still have the old condenser you may want to try putting it back in.

If you put the probe of your test light on the distributor wire small terminal of the coil it should flash as the engine is cranked over, if the points are working.

You asked earlier about other insulation, like between the points and breaker plate. That would be a NO. The points need to make a ground through the breaker plate and distributor body for primary current to flow through the coil. When the points open the circuit is broken and the electrical field in the coil collapses, generating the high voltage spark. So, if the points aren't grounded for some reason, you will not get a spark.

 

[Baumanm]

When using a multi-tester to test the coil/points/general function of the distributor, what tests should I run and where do I put the leads.

 

[JMOR]

(quoted from post at 16:03:47 12/12/21) When using a multi-tester to test the coil/points/general function of the distributor, what tests should I run and where do I put the leads.

f you insist on trying to learn to use a multi-meter............then disconnect the wire on distributor side terminal and set meter to lowest Ohms scale and connect one to lead to distr stud that you removed wire from & the other to good solid tractor ground. When running starter, meter should show continuity (low resistance value) when points are closed and show high value (no continuity/open circuit) when points open. You can observe those two extremes by touching meter leads together(continuity) and separating them(no continuity).