CarlB

My 8N started just fine this morning and was running great...then it just quit like I turned of the key and will not start again. The Sarter is cranking fine, but I have no spark at the plugs. I have voltage at the input side of the coil, but when I pulled a sparkplug wire and tried to jump a spark to ground...nothing. I replaced the coil, and still nothing. The rotor button looks fine too. any suggestions on what to try next?

CarlB

I didn't mention, this has a 12 volt conversion done a couple of years ago and I have had no problems what so ever with starting problems until now. - CarlB

Morgan

Did you turn the motor over to make sure that the rotor button was turning. Make sure that you are not out of gas, I know that has nothing to do with the spark but just check it.

__________________
""If you don't have dreams that are a little beyond your grasp, you have already started to die.""

78 acre hay farm
1965 John Deere 4020
John Deere 1209 Mower Conditioner
Woods MD 315 Batwing Bushhog
1952 8N Ford Tractor
1990 Yazoo 60" Deck with a 20 HP Wisconsin.
I work on a 1000 acre sod farm.

CarlB

Thanks, I have verified I have a full tank of gas..In fact it has overflowed out because I/ve been cranking it so much. The rotor button is turning. I replaced the condenser too and still no spark . I'm checking the spark by pulling a plug wire, inserting a scew driver into the wire cup and holding he shaft of the screw driver next to to the chasis..I can't pull a spark

dawzie

My 8-N has done the same thing more than 5 times. It's always been the points.

Take a test light - with key on - check wire going to coil - should be hot (light on) - then check wire between coil and disturbutor.

Crank motor over - light should go off and on. If it does blink, then it could be a bad coil.

If light stays on all the time, points are "open"
If light does not light, points are "closed"

I just take a feeler gauge and scrape the points contacts and it will run again for a few weeks.

I have found that the points from Tractor Supply don't last very long. I went to NAPA and they showed me the difference with theirs. The guy at NAPA also said to check the way the two little wires are connected on the coil. If your battery is connected as a "positive" ground, besure to have the wire from the disturbutor connected to the "+" (positive post) on the coil.

dawzie

__________________
"There's always time to do it right the second time"

CarlB

Symptom: This is a 1947 Ford 8N with a 12V conversion and front mounted distributor. It was running just fine with no problems of any kind. When the failure happened, I started the tractor and used it for about 15 minutes. The engine died just like I turned off the key. It would not restart.



What I've checked:

1) It's has gas, and the engine is getting gas.

2) There is no spark at the plugs. (tested by pulling plug wire and inserting screw driver into plug wire and trying to jump a spark to ground.

3) It has voltage to the input side of the coil.



I replaced the coil - no change in symptom.

I replaced the condenser - No change



4) I took the distributor off the engine and inspected the points. The points are opening and closing and look new. They are not burned.

5) I connected Ohm meter between coil output connection (This is the concave screw where the coil wire fit's into) and observed the meter bounces as the points open/close. So the points are not grounded. I checked the gap of the original points and it appears to be gaped correctly. I did not change the points or re-gap them because it all looks good.

6) I checked that the bottom coil wire was making good contact with the concave screw in the distributor.

7) I verified the rotor button is turning when the engine is bumped with the key.



What I have not done:

1) I have not replaced the rotor button. It looks brand new and does not have burn spots on it.

2) I have not replaced the distributor cap. It also looks brand new and show no signs of wear, or cracks.
3) I have not replaced the points, but verified with an ohm meter that they are not grounded and make/break connection when the distributor is turned.

dawzie

With everything connected, just try the test light test. I did an ohm test and everything seemed to have been OK also.

__________________
"There's always time to do it right the second time"

submoa

remove center high voltage lead at distributor (coil wire). position where you can see it near a ground 1/4 - 3/8 inch . put in neutral and crank to see if you have a bright blue spark. if you have spark at that point then you should check the rotor close as a hole sometimes develops thru the plastic insulation and the spark passes to the distributor shaft and grounds it out rather than going to the plugs. Good luck, Ed

Mike13

I know this is an old post but just thought I'd comment on....

"2) There is no spark at the plugs. (tested by pulling plug wire and inserting screw driver into plug wire and trying to jump a spark to ground."

I'm not sure that is a good test set-up. I'd leave the spark plug in the plug wire, ground the threads of the spark plug, & then see if you have a spark between the center electrode and the side electrode/threads.

Mike13

I know this is an old post but just thought I'd comment on....

"2) There is no spark at the plugs. (tested by pulling plug wire and inserting screw driver into plug wire and trying to jump a spark to ground."

I'm not sure that is a good test set-up. I'd leave the spark plug in the plug wire, ground the threads of the spark plug, & then see if you have a spark between the center electrode and the side electrode/threads.

Mike13

I know this is an old post but just thought I'd comment on....

"2) There is no spark at the plugs. (tested by pulling plug wire and inserting screw driver into plug wire and trying to jump a spark to ground."

I'm not sure that is a good test set-up. I'd leave the spark plug in the plug wire, ground the threads of the spark plug, & then see if you have a spark between the center electrode and the side electrode/threads.

johnnybuck

I see that this is post has had some very good suggestions as to what might be the problem. I have been using an 8n for several years and I would suggest checking the wires at the amp meter, if these wire are loose the tractor will not run at all. I hope this will help.
Johnny

GFC Firefighter

Check to see if fuel is getting to the carb
Check the fuel filters
Check to see if you are getting fire from your coil
Check to see if your rotor button is spaced out correctly
Check all wires to make sure none are shorting out
Check to see if all spark plugs are getting fire- if one isn't getting good fire this could be the problem.
Check the distributor cap
Check to see if the gas is going up to the engine so it can get fire
Check the Condensor within the distributor
Check the resistor

rsmith335

Mine did the same thing. Some idiot washed the tractor before it cooled and got water on the coil and cracked it. I wonder when the 12 volt conversion was done if they put a 12 volt coil in?