Hi folks, I've been lurking on here a couple years, since I bought my '49 8n (front mount distributor, 6 volt), and have so far been able to solve everything that's come up, mostly from advice I've found here, Which is something as I didn't know a thing about anything engine related before buying this tractor. So thank you!

But now I'm stumped. Here's the story.

Basically, tractor won't start. Two weeks ago I ploughed up 2 acres, and things were running pretty well at first, but then started straining under load a bit. I got to discing and only managed once over and the struggling under load was getting worse. Points looked a bit fried so I replaced them (bought a kit with new spark plugs too). All new plug wires and wiring harness as of March.

I've got a steady flow of fuel through the bottom of the carbn(recently cleaned out) and compression is 100-85-95-105 dry. The 85 jumped to 100 with some oil.

Sparks look good and blue to my eyes, but then my eyes haven't seen a lot of spark. Starter is cranking as well as ever.

Generator recently crapped out (I took it apart and cleaned it out and re-affixed the broken A to F wire), and so battery was dying, which is what I was attributing the rough running to.

I set the points according to manual.

I've got a 12 volt conversion in the mail so as to not have to buy a new generator.

Now, I'm back to thinking I've got a weak battery (charges up to 6.5, was starting tractor fine two weeks ago. When cranking voltage drops to ~5.0 and holds there), although it's fairly new. Anything else I can do to test that other than take it in?

Also, the previous owner installed an ignition switch (picture below) that I think has a voltage leak. The neg battery terminal goes straight to the switch, and the switch then goes to the starter solenoid. I can't quite figure out the implications of this on the electrical system, but am suspicious. I'm getting .3 volts to the solenoid/coil with the switch OFF. I always unplug my battery. I intend to replace the switch, but wonder if I should rewire back to the original wiring, and what sort of switch I should buy. Everything else is rewired according to the wiring harness directions, although I had to run a wire from the bottom terminal to the top right terminal on the block in order to get voltage to the coil (picture below).

There's probably more I could tell you, and I know I could probably spend a couple more days reading advice on here and trying things out, but I'm now in a time crunch to get the field ready for planting so I thought I'd reach out. It could well be something obvious that my inexperience/ineptitude missed.

Thanks in advance!

Pardon for any screwups with the photo uploads.
a223966.jpg

a223967.jpg
 
So all you have done is replace the points and cleaned the carb. Right?
Stop, do not change anything else until you have fixed this first.
Dont change to 12v until this is fine, it does make a difference.

Others will be along to help shortly.
 
(quoted from post at 12:40:49 04/16/16) Hi folks, I've been lurking on here a couple years, since I bought my '49 8n (front mount distributor, 6 volt), and have so far been able to solve everything that's come up, mostly from advice I've found here, Which is something as I didn't know a thing about anything engine related before buying this tractor. So thank you!

But now I'm stumped. Here's the story.

Basically, tractor won't start. Two weeks ago I ploughed up 2 acres, and things were running pretty well at first, but then started straining under load a bit. I got to discing and only managed once over and the struggling under load was getting worse. Points looked a bit fried so I replaced them (bought a kit with new spark plugs too). All new plug wires and wiring harness as of March.

I've got a steady flow of fuel through the bottom of the carbn(recently cleaned out) and compression is 100-85-95-105 dry. The 85 jumped to 100 with some oil.

Sparks look good and blue to my eyes, but then my eyes haven't seen a lot of spark. Starter is cranking as well as ever.

Generator recently crapped out (I took it apart and cleaned it out and re-affixed the broken A to F wire), and so battery was dying, which is what I was attributing the rough running to.

I set the points according to manual.

I've got a 12 volt conversion in the mail so as to not have to buy a new generator.

Now, I'm back to thinking I've got a weak battery (charges up to 6.5, was starting tractor fine two weeks ago. When cranking voltage drops to ~5.0 and holds there), although it's fairly new. Anything else I can do to test that other than take it in?

Also, the previous owner installed an ignition switch (picture below) that I think has a voltage leak. The neg battery terminal goes straight to the switch, and the switch then goes to the starter solenoid. I can't quite figure out the implications of this on the electrical system, but am suspicious. I'm getting .3 volts to the solenoid/coil with the switch OFF. I always unplug my battery. I intend to replace the switch, but wonder if I should rewire back to the original wiring, and what sort of switch I should buy. Everything else is rewired according to the wiring harness directions, although I had to run a wire from the bottom terminal to the top right terminal on the block in order to get voltage to the coil (picture below).

There's probably more I could tell you, and I know I could probably spend a couple more days reading advice on here and trying things out, but I'm now in a time crunch to get the field ready for planting so I thought I'd reach out. It could well be something obvious that my inexperience/ineptitude missed.

Thanks in advance!

Pardon for any screwups with the photo uploads.
a223966.jpg

a223967.jpg
iring not factory, but it has worked in the past & will no doubt work again. Need to begin with a fully charged battery. Try jumper wire between two top (resistor) posts of terminal block when trying to start. If it starts it will probably keep running when jumper disconnected.
No key switch, I assume?
 
Disconnect reg and Genny . Remove 6v bat and try her on 12. If it works, load test the 6v bat, and check connections
 
Foster.........ennytime you have starting issues, change yer sparkies. Recommend AutoLite 437's gapped 0.025. 2nd, when replacing sparkie wires, use old fashioned COPPER CORE 'stedda' modern string sparkie warrs. 3rd, points (0.015) are designed to be replaced on the kitchen table. (seriously) Me? fer a quickie, I'd clamp the corner of $1-bill (cheap) between the points and PULL. This will polish the INVISIBLE corrosion from between the points (0.015) Awe yes, compression; Ford specs 90psi min (dry) good runnin' N-Engines are about 110psi. Brand new rebuilt N-Engine about 125psi. The pixs of yer "infamous" ballast resistor ain't nuttin to write home about. And yer weak sister ignition switch is a known problem. By-passin' the ballast resistor will work fer a while until the internal insulative tar melts. This takes about 1-hour, the tar will solidify overnite. While there are arguments FOR 12-volt conversion, gittchur current 6-volt workin' rite ...then... think about 12-volts........HTH, Dell a 12-volt advocate fer the right reasons, that said, I haven't found the right reason fer my easy startin' 52-8N
 
Thanks Dell. Plugs are autolite 437s, haven't gapped 'em I'll try that, but they started up well enough a few days ago, and I've cleaned 'em a bit. I'm afraid the all we've got here is $5 bills, and they're plastic now!

I've checked the points a couple times, and it's started a few times fine since the new ones. I'll check again though.

Plug wires are copper core.

I ordered the 12 conversion when my generator crapped out, figuring it was cheaper than a new one.

JMOR, I'm worried the wiring wasn't the same before. My gf did the wiring harness, and I forgot to take photos beforehand, so she wired it according to the instructions, not necessarily how it was before... course, I hadn't realised at this point the wiring wasn't factory.

SouNdguy, couldn't that mess with my coil!?

Oh, and forgot to mention my starter solenoid was shorting and I think running the starter the whole time I was working and I didn't notice. Solenoid fixed, could that have done any damage?
 
Foster.......the little middle terminal of the 8N solenoid is GROUNDED by the BIG thumb switch at the tranny shiftier. Some people with size #13 brogans have been known to clomp on the solenoid shiftier wire and SHORT it to ground and cause the starter motor to continuously operate. Does it hurt it? Yeah it gitts HOT and you will melt some internal solder wiring. Then you'll complain and haffta replace the starter motor. Usually the starter bendix will disengage from the flywheel gears so the engine runnin' isn't runnin' the starter motor. .......HTH the amazed Dell
 
Sparks look good and blue to my eyes, but then my eyes haven't seen a lot of spark.

Checking the spark needs to be done with a tester or a spark plug with a 3/16" gap . If it will not jump a wide gap under normal atmospheric pressure then it probably will not jump the .025 under compression .
 

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