Going crazy with ignition problems

[Tall T]

OK folks, I have a 1948-49 8N with a front mount distributor. Got it from a buddy, it was his dad's tractor, last run around 2020. Buddy kept it covered so it was in relatively good shape, and he also put paint on it whenever he had some out and about, so it's pretty layered up with Ford red paint.

When I first got it, it had a Pertronix ignition system and wouldn't start. I put some new plugs in it, messed with it for a few hours, then we just pushed it on the trailer. He also gave me a ton of extra parts, including distributor points, some rotors, caps, capacitors, all kinds of ignition bits and bobs.

Prior to this, I had a 9N I got from him that was running with a brand new distributor, cap, and coil, and a rebuilt carb (meaning I replaced the needle and seat, and whatever other parts came in the TSC rebuild kit). I futzed around with the 8N for a few Saturday afternoons but never could get spark, and I wasn't convinced I was getting good fuel flow through the aftermarket fuel shutoff valve (no bowl or filter). I replaced ignition wiring and checked the side mounted coil resistor and all seemed well. Tried the coil that came with the 8N, various cap, rotor, distributor combinations, no love.

After the holidays, I decided to just go for broke and I took a bunch of good parts from the 9N to put them on the 8N, including a steel fuel line, the rebuilt carburetor, and new distributor, cap, and coil. Futzed around for another weekend but didn't really get anywhere. I also got several fuel bowl assemblies from my friend so I took one and rebuilt it with a fresh O ring as it leaked like crazy when I first tried it out. At this point I knew I had good fuel flow, as I could flood the carburetor if I choked it for too long. I have a spark tester and was checking for spark, and I was getting good spark at this point. When I FINALLY got it running last weekend, I put the original carburetor on it after I gave it a workbench cleaning and look-over (the float floats just fine, needle and seat were moving good), and I was using the brand new distributor, cap, coil, and rotor. However, it wasn't running quite right, it was periodically backfiring through the intake, and wouldn't run below about 1/2 throttle.

Did some more reading, and backfiring issues seemed to point to more ignition issues, so today I took off the distributor to see how it looked. The new distributor (which I did nothing to when I first got it except slap it on the tractor) has a really small points gap; smaller than 0.014, I didn't go any lower. I can't really get it to open up any further by adjusting the screws inside; I loosened the top and bottom screws and used the one in the middle with the cam on it to see how far I could get it to move out. I had put a new set of points on what I believe to be the original, pre-Pertronix distributor for this 8N, so I checked the gap on that one, set it to 0.015, gave everything a clean up, replaced the capacitor with a new one I had in the parts box, cleaned all points of contact in the cap and rotor, and put it all back on the tractor. I ran out of time today before I could do more detailed diagnosis but it seems like now I am getting no spark at all, or very weak spark. I cranked it with choke and gas came out of the carb but I didn't get so much as a single pop.

I'm beginning to feel like I'm running in circles here and burning a ton of time on what seems to be a very very simple system. At this point I think the only other things I can try is new spark plug wires, even though that rarely seems to come up in troubleshooting processes, or maybe a different ballast resistor? The plugs are carbon fouled from all the cranking I've been doing, I guess I could clean them too? Just looking for some encouragement and advice so I don't just say to heck with it and save up for a diesel tractor.

My Jubilee didn't want to start the other day and it hadn't been started in two months.
The weather had been cold and it's very damp in the tractor tent.
So . . . before too many "what-ifs" got the better of me, I warmed up the intake manifold and carb with a propane hand torch
and it fired right up. All subsequent starts have been quick and easy.

Have you tried a shot of ether?

If your backfires are out the tailpipe then the timing is too retarded;
if it backfires out the carb, the timing is too advanced.

T

 

[Mad Farmer]

My Jubilee didn't want to start the other day and it hadn't been started in two months.
The weather had been cold and it's very damp in the tractor tent.
So . . . before too many "what-ifs" got the better of me, I warmed up the intake manifold and carb with a propane hand torch
and it fired right up. All subsequent starts have been quick and easy.

Have you tried a shot of ether?

If your backfires are out the tailpipe then the timing is too retarded;
if it backfires out the carb, the timing is too advanced.

T

I wouldn't use a torch on the carb. I use a hair dryer, even then I'm careful of sparks.

I set that up ~1 hour before I try to start it, and put some aluminum foil around the carb/manifold to direct the warm air.

If I know I'll need to start things, I'll run an extension cord out to the tractor, and setup the dryer., under the tarp. Next morning I just need to flip the switch then go back inside and have coffee/breakfast.

 

[Kondoge]

How's the rest of your entire wiring looking, if there's a bad wire somewheres else like to the key or running to the distributor, then that would do it too however this is not in every case, mine wouldn't start and it turned out the coil and points had moisture in them which prevented spark, I also once had the distributor cap short and burn so bad it wouldn't spark anymore, and the past time it did this it started ran briefly then quit due to flooding, there are so many things that could cause the machine not to run, even bad valve clearances or a worn cam could cause it to run poorly. based on your backfiring timing or valve issue, possibly a flooding issue.

 

[dbsoundman]

Well, I got it running! A little weird how it all worked out. First, I pulled all the spark plugs and cleaned off the carbon with a wire brush. Turned on the gas, turned on the ignition…still not starting. Gas would drip out of the intake if I used the choke. But I got it to pop on some starting fluid. After a few tries I shut off the gas and added about a gallon of fresh fuel to the existing fuel in the tank. I forgot to turn the fuel back on, but I tried it again and it started right up! Then of course it died when it quickly ran out of fuel. Opened the fuel valve, gave it a couple more tries, and I finally had a runner!

 

[Kondoge]

so it was flooding itself? mine was doing the same would sit in the cold for 2 weeks then it would flood something terrible, then we would unflood it dry the distributor and try again, after that it would start.

 

[Non-farmer]

Gas would drip out of the intake if I used the choke.

Ns love to flood when choked. In my experience with mine, anything more than a second of choke - mayyybe 2 seconds - is begging it to flood, and it will oblige

 

[dbsoundman]

Ns love to flood when choked. In my experience with mine, anything more than a second of choke - mayyybe 2 seconds - is begging it to flood, and it will oblige

My only experience before this was a 9N with a very worn engine and it required a decent amount of choke, even after you got it started, before it was happy enough to stay running without choke.

 

[Kondoge]

Ns love to flood when choked. In my experience with mine, anything more than a second of choke - mayyybe 2 seconds - is begging it to flood, and it will oblige

Yeah it sucks especially when its cold and it needs the choke out to warm up, then floods out while running... this is why I keep 2 extra sets of plugs flood one set switch em out for a dry set. flood the other two sets and clearly something aint right that needs to be corrected. Can relate to the worn engine though, mines a 1940 9N with a 1949 8N engine that is not happy to be running again. though the other way to prevent flooding is a thing I call semi automatic mode, moving the choke in and out in and out until it runs and stays running, giving the engine time not to flood. or the other way is to start it from the ground (not recommended, that's how I figured out my interlock was not all it's cracked up to be anymore.) with the gas off crank it over, when it starts quickly open the fuel, if you do it right it won't stop and it will keep running as if you had started it with the gas on. this is my go to method but it can still flood with just what's in the carb which bred the start with the gas off, flutter the choke and turn the fuel on once its going, tactic.

 

[Ed S.]

Ns love to flood when choked. In my experience with mine, anything more than a second of choke - mayyybe 2 seconds - is begging it to flood, and it will oblige

It's even worse when it's cold.

 

[Kondoge]

It's even worse when it's cold.

That's what I'm sayin here In Alberta its horrible in the winter.

 

[Brhatweed]

Mine started cold without any torches on the manifold, just set the throttle to about 1/3 scale and cranked pulling the choke for two cylinders and open again and poof it starts.

See for yourself.

 

[Kondoge]

But then again side mount vs Front mount too.

 

[Brhatweed]

I'm on the side

 

[Ed S.]

That's what I'm sayin here In Alberta its horrible in the winter.

Somewhere in my files, I have a video of starting my 6V '50 frontmount at -4°F. Took a couple tries, and she only hit on two to start, then three, then all four.

 

[BodaciousGaming]

Bit late to the party here but I didn’t hear anyone mention spark plug gap. It’s my understanding that the Electronic ignition recommends a gap of slightly more than a points based distributor, especially if you’re using one of the hot coils along with it.

My fresh plugs out of the box came gapped at .32 and my 8N side dist is loving them there after I got the carburetor issue lined out.

 

[soaked]

Bit late to the party here but I didn’t hear anyone mention spark plug gap. It’s my understanding that the Electronic ignition recommends a gap of slightly more than a points based distributor, especially if you’re using one of the hot coils along with it.

My fresh plugs out of the box came gapped at .32 and my 8N side dist is loving them there after I got the carburetor issue lined out.

Your post got me thinking.

Pertronix 1244A (for sidemounts) info sheet says the spark plug gap can be opened .005" over stock.
First and last Ford owners manuals for 8n both give .025 - .028 range for plug gap. So FM and Sidemount share the same spec.

Pertronix 1247, ( for FM ) info does Not give the .005" increase.

Suspect a bigger gap causes too much heat for FM square coils...

See long ago JMOR (RIP) posts here:

https://forums.yesterdaystractors.com/threads/pertronix.282367/#post-1173471

 

[8mfriend]

My only suggestion would be to make sure you have a good ground, and a strong 12v to the coil, you may even run a hot wire directly to the coil to see if it helps - my tractor is currently running off the battery and wired directly to the coil, just make sure to disconnect that wire after you test it - or you will burn up the coil - I have limited experience with these tractors, but I know mine requires a good ground and good 12v or it doesnt run well, if at all.