Ford 9N Ignition Issues

Couple of updates on the 9N.

This morning I started the thing up after it had been sitting since Sunday evening to see if it held prime. Sure enough, the oil pressure came right up, and actually came up faster with the straight 40 than it did with the 15W-40. So it seems like the straight 40 does a better job of keeping the prime. That's a good thing.

However it seems like the carb is leaking internally some amount and it'll flood the engine very quickly if I don't shut it down with the fuel as opposed to shutting it down with the ignition. I didn't have this problem before the engine overhaul with the last carb. I shut it off with the key then thought I should restart it and let it shut off with fuel, and the thing was flooded in a matter of seconds. Not sure if there's something I can do to try to fix that other than replace the carb.
 
Float stuck open? If the bowl overflows does it vent to the ground or go into the intake?
 
Bill Jennings said:
Float stuck open? If the bowl overflows does it vent to the ground or go into the intake?
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I've thought about the float stuck open idea. I do notice the bowl seeping some around the top gasket, but it also wouldn't surprise me if some was leaking into the intake.

I know it ends up being flooded - when that happens it'll puff a bit and I have to turn off the fuel and crank it at full throttle for a while and a few puffs before it'll actually run.
 
Or crapola in the needle and seat. Could possibly explain your other problem as well.
 
Flooding w/ the fuel selector left on is fairly common, but not in there amount of time you mention. I always turn the fuel off right after shutdown or else they can be tough to start. Sounds like the float is sticking in yours, I’ve also had that happen and it wept around the gasket.
 
Yeah, stuck float sounds possible. The carb is brand new so junk in the jets seems less likely. For now I'll just keep disciplined about turning off the fuel to shut the thing off. I do this on my MF 165 as well because it will flood too, although not as badly.

It is also possible that this carb I got (which was new) is just poor quality.
 
Stuck bowl, turn the gas on, whack the bowl a few times with a screwdriver handle, see if it stops. If not, turn off gas, take off bowl, spray liberally with carb cleaner. Clean out bowl and focus on needle valve and seat. Hold float up with finger, gently, you should see about a 1/4 inch gap between the float top and carb bowl gasket. Make sure float is not filled with gas. If all this is ok, then turn on gas while holding float up. No gas should come out. Then lower float, gas should flow, then gently push float back up. Gas should stop. If this all is ok after the cleaning, put it back together and start it up. Otherwise, if you saw a problem, you know what to fix. I wouldn't just buy another carb until you figure out what's up. Also make sure there is a fuel filter that is in good shape, plus make sure gas line is ok, after a while they can disintegrate sending pieces of rubber or rust to cause havoc.
 
Ted DuPuis said:
Not sure if there's something I can do to try to fix that other than replace the carb.
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Fix it. Most new parts are being made in India, Vietnam, and China and are rebranded regardless where you buy them. Sounds like stuck float which could also be your stumble issue. If your leaking fuel that fast after shutdown it will also cause you to run rich. Normally it should take overnight to leak (a little) if you leave the fuel on. Pull the carb and soak the whole thing in carb cleaner then blow it out and try again. If still flooding check float/needle settings. Or do the reverse.
 
And do be sure to have an effective fuel filter upstream of the carb such that the float/needle/seats don't get crudded up with mystery spooge.
 
Where's the OE? Is it a Marv Schebler? OH kits for those things are like $10. The only special tools you need are a screwdriver with a blade broad enough to bridge the slots in the needle seat. Some guys use a dime and a set of needlenose pliers.
 
I don't know that the float needle looks like, but if it has a rubber tip like the old Stromberg/Bendix aircraft carbs, it might be swollen, depending on the rubber compound they used to make it. The older ones would swell when hit with ethanol, and they would stick open or shut or somewhere in between and cause all sort of issues. If it's some offshore clone, that might be the problem. Quality isn't a big deal with some of those places.
 
All this talk of priming the oil pump after it has been sitting for a while...surely this was not required when they were new? It was not necessary on my late FIL's 8N. I have heard that worn pumps will lose the ability to self prime. Also, to replace the pump housing on a 9/2/8N I understand that it is part of a main bearing cap and so would require align boring to fit. Perhaps the hassle/expense of this leads some to mess around with vaseline, priming with gear oil etc.
 
flyingbrit said:
All this talk of priming the oil pump after it has been sitting for a while...surely this was not required when they were new? It was not necessary on my late FIL's 8N. I have heard that worn pumps will lose the ability to self prime. Also, to replace the pump housing on a 9/2/8N I understand that it is part of a main bearing cap and so would require align boring to fit. Perhaps the hassle/expense of this leads some to mess around with vaseline, priming with gear oil etc.
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Assuming the pickup is in good shape, what happens is that the pump bodies wear, and though the gears may be replaced at OH, the body is out of spec and the clearances too great to hold prime. The bodies can be repaired by a good machinist, but most guys don't measure , and probably wouldn't care to spend the $ and think gears will be enough. As far as packing with vaseline, even brand new pumps need that to draw initial prime. You can't attach a drill and spin it like you can an auto oil pump. Packing is a good idea no matter what with an oil pump. The vaseline just harmlessly liquifies into the oil after it does it's job.
 
flyingbrit said:
All this talk of priming the oil pump after it has been sitting for a while...surely this was not required when they were new? It was not necessary on my late FIL's 8N. I have heard that worn pumps will lose the ability to self prime. Also, to replace the pump housing on a 9/2/8N I understand that it is part of a main bearing cap and so would require align boring to fit. Perhaps the hassle/expense of this leads some to mess around with vaseline, priming with gear oil etc.
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While I doubt this was as much of an issue when the things were new, the design isn't particularly ideal compared to what we have now.

In my case, the tractor engine had a lot of issues when we bought it. It had a rod knock, and upon tearing it down it actually had 4 rod knocks (yes, all 4 rods knocking). The people my wife bought it from said it wasn't running when they got it and they'd done some engine work. What I found was that it looked as though they'd installed standard bearings when the crank had been ground undersize, and they replaced the oil pump without doing a line bore to machine the block. So lots of reasons why it could've been losing prime. Even then, it would keep prime so long as I ran it every day, but if I let it sit more than a couple of days it'd lose the prime.

So far, it seems to be doing a lot better on the rebuild. However it's not sat for a week or more. The big thing I notice is on cold starts it comes up to pressure essentially instantly.
 
flyingbrit said:
I have heard that worn pumps will lose the ability to self prime.
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That's one reason but a cracked/loose pickup tube can cause that also and is more common. There is also a solder joint on original tubes that would crack at the tube mount flange. Same if the wrong tube was installed and it hit the crank and had a hole worn through it. But most would rather deal with priming each time than split the tractor or drop the oil pan to fix it.
 
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Bell206 said:
That's one reason but a cracked/loose pickup tube can cause that also and is more common. There is also a solder joint on original tubes that would crack at the tube mount flange. Same if the wrong tube was installed and it hit the crank and had a hole worn through it. But most would rather deal with priming each time than split the tractor or drop the oil pan to fix it.
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I was told the oil pickup tube was the likely cause for my priming issues. When I tore the thing apart I saw nothing to indicate to me that was actually the cause. So I put the same pickup back in.
 
The small Continentals--A-65/75, C-85/90 were famous for losing prime when they sat. My A-65 did it all the time, as did an A-65 in a Champ I flew. The problem is the oil pump cover: it's a metal-to-metal seal on the accessory case's pump housing, and it can leak real slow, leaving the gears dry after a while, and they were never designed to pump air, so they don't suck the oil up from the case. A worn pump bore doesn't help at all. I tried several different sealants on that cover, but none worked. One has to be careful, as you don't want sealant breaking off inside the pump and perhaps damaging something. I finally built a manual preoiler for it. Clamped it to the engine mount and ran a hose to an intake tube that clamped to the oil tank's filler neck and down into the oil. The outlet went to a check valve and shutoff valve I also built, and then to a tee in the oil pressure gauge line. It pumped oil into the gauge port on the engine, filling all the galleries all the way around and into the oil pump itself, priming it. Oil pressure would come up instantly when I started the engine.

This was in a homebuilt, so don't ask me for one on an STC.

Maybe your Ford has the same sort of problem with that pump. Is it a plain metal cover with no seal of any sort?
 
Dan Thomas said:
Maybe your Ford has the same sort of problem with that pump. Is it a plain metal cover with no seal of any sort?
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I'm trying to remember now. I do remember having to put a paper gasket in between the pickup tube and the oil pump. I don't think there's a metal plate on the front of the gearset, but now I forget how exactly that worked.
 
PaulS said:
Stuck bowl, turn the gas on, whack the bowl a few times with a screwdriver handle, see if it stops.
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My first thought as well. Also thought old tractor, old fuel line and fuel tank, trash in the needle and seat. Then thought ethanol laced fuel. A leak in the float could be the culprit as well.

I have worked on a lot of old vehicles that had dents on the top of the carburetor....:lol::lol:
 
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Dan Thomas said:
Is it a plain metal cover with no seal of any sort?
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Ted DuPuis said:
I do remember having to put a paper gasket in between the pickup tube and the oil pump.
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The oil pump cover plate has a gasket. The plate is actually part of the pickup tube which is soldered into/onto the plate. The pump housing is part of the front main bearing cap and contains the gear set.
 
At this point I’m ready to call the project completed, at least for the moment. The engine is holding prime and making good oil pressure. I put on a new cork gasket on the fuel bowl. These bowls need the corn gaskets, rubber doesn’t seal properly.

I also welded up a bracket for the alternator. Previously I’d been using a strap to keep it tensioned, obviously a temporary solution, and the hood is bolted back on properly.

At some point I need to look further into the carb issue. I did tap the fuel bowl with a screwdriver but didn’t let it sit to see if it stopped flooding or not.

Either way, the 9N is now parked in the shed instead of in front of the garage, so that’s done enough.
 
Ted DuPuis said:
At this point I’m ready to call the project completed, at least for the moment. The engine is holding prime and making good oil pressure. I put on a new cork gasket on the fuel bowl. These bowls need the corn gaskets, rubber doesn’t seal properly.

I also welded up a bracket for the alternator. Previously I’d been using a strap to keep it tensioned, obviously a temporary solution, and the hood is bolted back on properly.

At some point I need to look further into the carb issue. I did tap the fuel bowl with a screwdriver but didn’t let it sit to see if it stopped flooding or not.

Either way, the 9N is now parked in the shed instead of in front of the garage, so that’s done enough.
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Sounds good, just be careful with the leaking gas thing, you don't want it to turn into a flambe, especially with a kid on it.
 
PaulS said:
Sounds good, just be careful with the leaking gas thing, you don't want it to turn into a flambe, especially with a kid on it.
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The carb doesn’t leak any gas externally while running.
 
Today I started up the 9N after it sitting since the weekend. Oil pressure came up instantly! Good sign.
 
The other day I started up the 9N. It had been sitting for about 2-3 weeks without running. The oil pressure took a few seconds to come up, but it came up on its own without priming. So I think I'll consider that problem to be resolved.

I haven't messed around with the carb or anything yet... the tractor works and I have other things that I'm working on now project wise, so I'm not going to mess with it at all.
 
A simple accumulator with a solenoid could help the prime. I've seen that on some airplanes!
 
Kenny Phillips said:
A simple accumulator with a solenoid could help the prime. I've seen that on some airplanes!
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Yeah but that’s work, and I have a lot of other machines that need work and a car that needs built. :)
 
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