8n no spark

db12567 · Jun 23, 2013

This time I gigged myself. After pushing some dirt around I got off and left the key turned on. Killed the battery and the coil.
8n front dist, 12v conversion. After charging I have crank but no start. Fuel is good, There is no spark at the plugs. So far: New coil as old one actually cracked. Since I pulled distributor to replace coil, changed points, cap, rotor and cond. I have 12.6 volts at top of coil with key on. Crank produces no spark. Rechecked gap and confirmed rotor is turning. Bench checked continuity from points while turning. Plug wires are good by meter read. I replaced my amp meter just for grins but I"m stumped. I"ve had the distributor off a dozen times checking and rechecking. The advance is good, all nice and clean and the springs not broken. Could use some suggestions.

Janicholson · Jun 23, 2013

Melted insulators in the conductors. Was the old coil good? Does it spark is you open the points by turning the engine to cam them open, then use a screw driver to bridge across them (as though they were turning. this simulates real points action. If spark, the points are dirty at the gap from being left on with current flowing through them. Jim

db12567 · Jun 23, 2013

The old coil was fine until I left the key on. The points are new. You're suggesting hand turning the engine to open the points and then bridging but the cap has to come off to do that and that in turn removes the coil power contact so there would be no spark.

Tom vertiz · Jun 23, 2013

Here is what I have found, put the distributer together on the bench with the coil mounted. You should be able to turn the distributer by hand from the slotted part on the side that mounts to the block,that turns the rotar. Check for continuaty from the scew on top of the coil to any part grounded on the body of the distributer. If you have continuity on and off while turning the rotar by hand it should be ok. If it always has or does not have continuity something is wrong.

db12567 · Jun 24, 2013

Sighhh. Looks like its coming off one more time. I"ll run that procedure. I"m leaning towards a defective(but new) coil or condenser. Thanks

old · Jun 24, 2013

Before you take it off again try this. Take the wire off on top of the coil. Turn the ignition on. Touch that wire back on and off the coil. You should see a spark when doing so if the points are closed and no spark when the points are open. You cna take thew distributor cap off and look in to see when the points are open and closed. If you have a spark when the points are open you have a short in the distributor and most likely the wire from the condenser

Tom vertiz · Jul 2, 2013

Did you get this working yet? I found if you put the distributer on wrong it will push the rotor up a little bit and there is a snap ring kind of wire that holds it together. That wire grounds out the pigtail on the coil and you get no spark. It is best to put the distributer on in three separate pieces, the body the cap and the coil. Make sure the ring is down in the groove all the way. Put the body on and turn the rotor by hand until it snaps in to place. Put just a little pressure on the body by hand tightening the bolts. Good luck if you have not yet figured it out.

db12567 · Jul 14, 2013

Yep..got it running. The ground bridge from coil neg to the ground plate on the points was cracked. Still made contact but suspect so I made a new one. Got to be pretty quick at pulling that distributor. Don"t know how many times stared at that setup and still didn"t see the cracked bridge. Kept measuring points open and close but they weren"t connected to the coil..I appreciate your suggestions and help..

8n no spark

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