8N doesn't start

[CraigM]

The tractor stopped working last year. It had spark, so tore into the fuel system and found it plugged by all kinds of gunk. Cleaned out the line from tank to carb, and the carb itself. Replaced the gaskets and reasembled. Fuel comes out of the carb drain, so it's getting that far. Pulled the rear spark plug after a few minutes (not continuous) of cranking and it didn't seem wet at all, and didn't smell of gas. Shot a small amount of ether starting fluid directly into the spark plug hole, reasembled...nothing. That plug would spark if connected to the wire and laid against a ground, so I know it's getting a spark. Checked the next one forward out of curiosity, and it is working also. Getting desperate now, so seperated the carb from the manifold a little and shot more than a little ether into it by putting a WD-40 'straw' onto the ether can and slipping it between the seperated pieces. Tightened it up and tried again. Not even a poof.

So, it seeems to be getting a spark, but won't even sputter with ether. Any suggestions?

 

[DJ54]

If it had that much gunk in the system, it may have sucked it into the jets, and have them plugged. I'd pull the carb., drop the bowl, remove the jets, and give it a good cleaning with spray carb cleaner. Just be sure and turn your head, or wear safety glasses when you give it a shot.

You may want to try and put a dab of gas in the cylinder, and try that. About 1/4 of a cap full from a plastic soda bottle should be plenty. The ether may be evaporating before you get the plug in. Although it should do something if sprayed in the intake. You'll dry your cylinder walls out if you use too much. It is a last ditch effort around here..

Maybe before even trying that, check your air filter, mice have been known to build in those oil bath filters.

It all boils down to the checking the basics.. Air, fuel, and spark. If you have all three, it should at least give you a "pop"...

 

[J_J]

If your compression is good, and the valves are not stuck, then with spark and gas/ether, it should fire.

Does it have suction on the carb when you crank. Are you trying to do this by your self.

Take all the plugs out and do a compression test, and write down the results. You said all plugs were firing. Is the fuel fresh? Is the shut off valve on. I have to turn mine off after I stop for the day. . The carb drips even after rebuilding.

 

[Egon]

Screw out the carb jets, turn it over a few times and then set jets to where they should be. May have to make some adjustments to them afterward.

If possible give the jet screw holes a blast of compressed air.

 

[CraigM]

I've already done most of all that. Blew out the carb and all the passages before reassembling, checked the air cleaner, no mice or other stuff, it's got fresh fuel, it will suck a paper towel into the intake on the side of the hood when cranking, fuel shutoff is on and I have a helper. I wondered about the ether evaporating before getting the plug back in, that's why I tried seperating the carb from the manifold and spraying it into the air passage. Thre was enough there not to evaporate, and if it did, it should have just stayed in the plumbing. Have not done compression check. It ran before, there is no good reason to think that it suddenly doesn't have enough compression to at least sputter. Yes, I don't want to bother with compression checks. My mind was running on this while I ran a few errands and it almost has to be a fuel issue. I was headed back out to the shop and was going to try priming the carb with gas, but I like the idea of backing out the needle valves. Much easier. Can still prime it with gas if that doesn't work.

 

[beenthere]

If you put in starter fluid, and it wouldn't fire off, then I think you don't really have enough spark. Put a tsp of gas in each cylinder, the plugs back in, and turn it over. If spark isn't the problem, I think it will fire a bit but may not run.

You haven't said what you did with the coil, condenser and points, rotor cap, plug wires, condenser wire. ??
Replaced? Look ok? filed points? anything?

Buddy just worked on his 8N, and found that the replacement parts were defective (finally put in the old condenser, and got it running again).

And I'd only use ether in the air intake as I was cranking. Less chance of a big bang that way.

 

[Soundguy]

no cough on start fluid means no spark. or no compresion like a stuck intake valve.

comp is easy to check with your thumb and the plugs out.

spark should be bright and snappy and jump a 3/16 air gap.

If you have good spark, try new plugs.. sparking under compression with a near fouled plug is different than sparking in the open air.

fire order is 1-2-4-3

soundguy

 

[CraigM]

Ok, I've tried backing out the needle 2 turns and cranking. No luck. Tried a little gas directly into a cyl through the plug hole, no luck. Then we dropped the carb off the manifold and hung it there by the fuel line and a piece of wire. Hooked the large intake tube back to the carb and blew gently into it with the air hose using a rag to stop up most of the pipe around the air nozzle. Droplets of fuel came up out of the main jet, so the carb seems to be working. There was a little gas lying in the bottom of the carb when we took it off, consistent I guess with droplets drawn out by the engine but not sucked into a cylinder. We put the carb back with a pretty good load of starter fluid in the bottom, no luck. Yes, I know that's probably getting a little aggressive, but there is no good way to get the ether into the induction system through the air cleaner. About that time, I'm beginning to wonder if drawing a spark against the block may be different than with the plug installed. Thank you Soundguy, for confirming that. Seems like at least one should be able to at least make a sputter, but I gotta get this thing out of my shop so I'll be replacing the plugs next week, after the incoming cold snap clears out and I've had time to get to town.

As for the
>>coil, condenser and points, rotor cap, plug wires, condenser wire. ??
Replaced? Look ok? filed points? anything? <<

Haven't messed with any of it. They look ok. When we first started this, we checked for spark. It was bright blue and snappy. Since then it seems to vary a lot. Could be that I'm not picking good grounds to test against, or maybe those parts need replaced. If plugs don't solve the problem, I'll look at those other things more closely.

 

[DJ54]

You may even want to pull the distributor cap, and look inside. Sometimes due to ionization there will be a buildup of matter on the lugs. I've had more problems with this on the newer aluminum lugs, than the old copper ones. It scrapes off pretty easy with a pocket knife.

Brighten up the rotor button too... Easy things to check...

If they would happen to be Champion brand plugs... We always had problems after putting in a new set. We found that it had to do with the coating that is put on them from the factory, and would cause carbon buildup. If you have one of those little sandblaster plug cleaners, you can clean them, and they will run a good while... I've had the same set in my Super C Farmall for 10+ years.

 

[CraigM]

I don't have one of those sandblaster plug cleaners. Do the Autolite plugs have the same problem? If not, I'll just get them.

 

[DJ54]

Autolites in my opinion did seem to work better. Champions are OK, but if I had my choice, I'd go with the Autolites. Sounds like I'm contradicting myself, but Farm & Fleet had a sale on them years ago, and of course I can't pass up a bargain, just had to get 10 sets. But you have to understand I had 7 tractors in my collection, that used that plug. When we would show them, I'd always have a couple extra sets in the toolbox.

Once the Champions were cleaned, they are OK... You may do as well with a small wire brush and some carb./brake cleaner. Even the Harbor Freight plug cleaners do a decent job. You can mount them on the wall, where it's handy to get to. It takes longer to remove and install the plugs, than it does to clean them. Just make sure the sand it all out of the plug when done.

Start with the easy items, such as cleaning, checking gaps, check for burned points, etc. If the spark in somewhat weak, it may be the condensor getting weak..., or just simple corrosion.

And something else that just came to mind.. You didin't say what year it was, or what type of cap is on the distributor. Square (Rectangular), or round. If it is round, is there a possiblity it may be off 180ｺ..?? Although it may cause it to fire on exhaust, but may be worth checking. It has been known to happen... You'll have good spark..., just not at the right time...

 

[J_J]

CraigM,

You never did say if the plugs were even wet. Take the air intake off the carb and squirt some ether in the carb while cranking, and if it don't cough, fire or something. Even if the cap is 180 out, with ether in the chamber, it should fire, pop, etc. There is no reason that ether won't fire with a good spark.

 

[Soundguy]

I prefer autolite 437.. though alc7 and the h10 or 12 work.. ( al 216 as well ).

don't forget to clean a plug that has been blasted with spray carb cleaner as it will have abrasive debri up near the insulator you can't see.. a surprising amount too!

soundguy

 

[Soundguy]

IMHO.. that's BAD advice. A wire brush can leave metal particle tracks on the porcelan (sp?) insulator.. and lead to fouling.

abrasive cleaning works darn good.. if you clean the abrasives out afterwards..

soundguy

... You may do as well with a small wire brush and some carb./brake cleaner. ..

 

[CraigM]

My wife had to go to town today and offered to pick up plugs for me. I gave her the Autolite and Champion numbers listed in the posts. The autoparts store didn't have either, but crossed the Champ # to Autolite 4316. That scares me as I've always seen Autolite 437 spec'd for 8N. Should I hold out for 437, or figure that 4316 is 'close enough'...a phrase that always worries me. When I do finally get plugs that I'm comfortable with, what's the proper gap?

I don't know the distributor cap shape. Never looked that close. I was hoping not to have to get that into things as it looks ugly to actually get to the cap. Don't know the year either. It's not my tractor, my son and I are working on it for a friend with no time or indoor shop facilities. It ran last year, but sat for a long time and then was dead. He and I figured it'd be simple and good experience for my son. It has been....and then some.

We did finally get the plug wet with tons of cranking, but it wouldn't fire, even with the ether in it.

I really appreciate you guys talking me through this.

 

[DJ54]

"IMHO.. that's BAD advice. A wire brush can leave metal particle tracks on the porcelan (sp?) insulator.. and lead to fouling."

I won't disagree with that a bit. But if he doesn't have a plug cleaner, and not the right plug at the moment, and wants to get it running, I'd give it a try. That's all we did for years till we got our plug cleaners.

I suppose a good stiff toothbrush would work too if the carbon deposits aren't too hard.

If the cap hasn't been removed, it shouldn't be 180 out. Guess I was thinking i read where you had checked to cap.. Guess I misunderstood...

But I would take a peek under it, and check for buildup on the lugs. I got a buddy of mime's 9N running several years ago, and this was the problem.

 

[J_J]

If it don't fire with ether, I don't think it is sparking. Are you using the 6 volt system or the 12 v system? Try taking all the plugs out and lay them on the block with the wires connected and crank the engine, and see if any or all the plugs are firing.

 

[GPintheMitten]

I think it is great that you and your son are working together to help your neighbor out. I know it is hard when you don't know the machine. Here's what I suggest.

If you want to help your son have a good experience in his first repair job, start him off right by getting the manual, read through the pages about the ignition system and tune up procedures. The owner can get a manual from stores like TSC, maybe from New Holland as well. For all the time you are putting into it, a few $$ for a manual is probably worth it. My recollection is that they cost about $15-20. The old Ford manuals are very easy to follow, with lots of black and white pictures.

Also, are you sure it is an 8N, or could it be a 2N or 9N. Lot's of people call them all 8N's. While all three are similar, there are differences related to the distributor and perhaps some other parts of the ignition system. The manual for the Ford 8N, 9N, and 2N will help you discover which you have by looking at serial numbers and matching pictures to what you have.

The other differences you run into is that these were built as 6 volt machines and some people have changed them to 12 volt. You need to determine which you have if you are going to replace certain components. Mine was 6 volt, so I'm not sure which components are different in 12 volt.

It certainly is a good idea to replace the plugs they are cheap so go ahead and replace them whether it is the root cause or not. The manual will tell you what plugs and the gap necessary. Then if it doesn't start, you really need to check the other components which means you'll have to check the distributor. With a manual you should be able to do that.

It has probably been a long time since it has been properly tuned, so you might as well replace points and condensor as well. How are the plug wires? Are they frayed or cracked? If you replace them, make note of which wires go where on the distributor and cylinders. You might need a new distributor cap.

I think a thorough tune up will reward the owner and make you and your son feel great about the experience.

 

[Soundguy]

a 4316 crosses over to an H10C.. so yes.. it will screw intot he hole and make sparks.. it would NOT be my first choice. A champion H12 ( 512 ) would be a better option.. a motorcraft al7c is also a good fit and is the current oem plug specified by CNH.. etc.

soundguy

 

[Soundguy]

Also, are you sure it is an 8N, or could it be a 2N or 9N. Lot's of people call them all 8N's. While all three are similar, there are differences related to the distributor and perhaps some other parts of the ignition system. ..

You are making this too hard. Ford N series used 2 distribuitors stock.. a side mount.. and a front mount. front mount was the same for the 9n, 2n, and early 8n.
parts for the frontmount fit all the front mounts. parts for the side mount actually fit all the 4 cyl gassers up to 64.

The manual for the Ford 8N, 9N, and 2N will help you discover which you have by looking at serial numbers and matching pictures to what you have..

Not even that hard... 3spd tranny = 9n/2n 4spd tranny = 8n

big rear axle nut = 8n.. smooth or rivited rear axle hub = 9n/2n

still.. the engine will have a sn on the side, above the starter, below the head that will tell you what the engine went to. All N engines swap.. so then you date the codes on the chassie to see if your engine matches your chassie.. general thoughts are if the casting codes and engine number all meet up within about 3 months or so.. you got a machine with no major swapped components.

soundguy