Lost Spark

[Larry Barnes]

There I was, brush hogging the horse pasture on my 8N. Made a couple rounds and while under stress, it quit. Turned off the PTO power and it re-started. Turned the PTO back on and resumed hogging. Made it about half a lap and it quit again. This time no re-start. Checked fuel tank and bowl, no problem. Took out two spark plugs and there was no spark on either one Took off side mounted distributor cap and rotor and cleaned the points then re-set gap. Took a screw driver and touched the points together lightly to see if there was power there, and yes, it sparked. So I put the cap back on and looked for spark at the plugs. Nothing.
the tractor is still sitting in the field. So now I'm wondering what to try? Earlier this year I replaced the plugs, points, cap and wires. They've been working fine. I do not recall changing the condenser. Do they die instantly? Or while running? What else can you recommend trying?

 

[JMOR]

(quoted from post at 15:11:20 06/02/21) There I was, brush hogging the horse pasture on my 8N. Made a couple rounds and while under stress, it quit. Turned off the PTO power and it re-started. Turned the PTO back on and resumed hogging. Made it about half a lap and it quit again. This time no re-start. Checked fuel tank and bowl, no problem. Took out two spark plugs and there was no spark on either one Took off side mounted distributor cap and rotor and cleaned the points then re-set gap. Took a screw driver and touched the points together lightly to see if there was power there, and yes, it sparked. So I put the cap back on and looked for spark at the plugs. Nothing.
the tractor is still sitting in the field. So now I'm wondering what to try? Earlier this year I replaced the plugs, points, cap and wires. They've been working fine. I do not recall changing the condenser. Do they die instantly? Or while running? What else can you recommend trying?

hen cranking it over, with cap off, are points showing an arc as they open?

 

[LBarnes]

The points go open and closed, just as they should. Is that what you mean...thanks for asking

 

[Mad Farmer]

Try running a jumper from bat to coil, if it runs O.K. problem is towards bat from coil. Don't leave jumper on except to test, it can damage points/coil.

Coils will do that when they get hot if above don't get you running. Ign switch will do that if it does run.

 

[Larry Barnes]

You mean I should hook my battery (plus or neg?) to the coil, which would bypass my ignition switch and that would rule out a failed ignition switch? Larry

 

[JMOR]

(quoted from post at 16:42:18 06/02/21) The points go open and closed, just as they should. Is that what you mean...thanks for asking

o, I mean, do you see a spark/arc at points when they open?

 

[Larry Barnes]

And how do you test a coil to see if it's good? As stated, I've got Juice at the points, just no spark at the plugs...Larry

 

[Larry Barnes]

When I stick a small flat screw driver between the open points, it sparks. (Wasn't looking at a spark plug at the same time though. Just the points)

 

[JMOR]

(quoted from post at 17:09:02 06/02/21)
When I stick a small flat screw driver between the open points, it sparks. (Wasn't looking at a spark plug at the same time though. Just the points)

ommunications like this just has to be so d--n difficult! I know you made it spark with a screwdriver, but...what I am trying to get you to do, is to verify that the points are actually conducting current and NOT just that they are physically opening and closing.

 

[Eman85]

If you own an N you should own a points file. A test light attached to ground touch the coil input you should have power. Touch the side that goes to the coil and it should blink when spinning motor over if the points are working.

 

[Mad Farmer]

(quoted from post at 13:59:27 06/02/21)
You mean I should hook my battery (plus or neg?) to the coil, which would bypass my ignition switch and that would rule out a failed ignition switch? Larry

MAKE SURE IN NEUTRAL!!! Pos if - ground, Neg if pos ground. Same side of bat hooked to ign switch.

That puts bat voltage to coil.

I have a front mount but the coil slowly went away and it drove me nuts for two years. Started and ran great until it got hot. First started summers brush hogging, winters didn't happen. Then would die after a few minutes work.

 

[Jim L WA]

You had asked if a condenser could just go bad. The test that JMOR wanted you to do was to confirm that the condenser was good or bad. If the points arced/sparked while cranking then the condenser is bad or there is not connection to it.
Usually if the coil is going bad, after cooling down, the tractor will start and run for another 10 minutes of so and then quit again.
It's your call, but condensers don't cost much while not true with a coil.

 

[Larry Barnes]

(quoted from post at 17:32:02 06/03/21) You had asked if a condenser could just go bad. The test that JMOR wanted you to do was to confirm that the condenser was good or bad. If the points arced/sparked while cranking then the condenser is bad or there is not connection to it.
Usually if the coil is going bad, after cooling down, the tractor will start and run for another 10 minutes of so and then quit again.
It's your call, but condensers don't cost much while not true with a coil.

Thanks for your input guys. It's been raining here and the tractor is still out in the field. I'll try this stuff and get back at you.

 

[fusion1]

Make sure you check the Ign Switch
I has a Ferguson TO-30 it kept shutting off it took me awhile before I found
the trouble her the Ign Switch was bad it was turning on ok but something was wrong internally
replace the switch and was ok

 

[Larry Barnes]

Hi Guys...turns out it WAS a old coil that needed to be replaced. Fired right up after replacement. Thanks for your input from everyone!