9n Ford makin my grey hair white

jkouba

New User
Land Lord has a 9n ford he probably puts 40ish hours a year on spraying food plots and leafy spurge

Found him while spraying wheat on his ground down in the river bottom the old girl died on him. Found the key switch was shot and jumped wires together and he got it home fine

Put a new switch in and wire from the starter solenoid to the up by the resistor. And a new wire from the resistor to the coil.

Life is good for another day

While he's out again it starts starving for gas, only runs with the choke on

He decided he wanted a new carb cause the old one has bad throttle shaft play

Went out to throw it on and it only starts and runs with the choke. Turns out the intake/exhaust manifold had come somewhat loose and destroyed the gaskets.
The manifold was shot so got a brand new one and gaskets, way overdue for that

Put it all together, starts up, idling smooth as can be the engine dies..... got no spark

Pulled apart the distributor, nothing seems to out of whack, I put new points, cap, rotor, condenser, coil and resistor about this same time last year.

When I pulled the wires out of the cap I noticed cylinder 3&4 if I remember right the rotor had been kissing them quite hard, reassembled the distributor and spun by hand and couldn't spin it out between them two holes, it would get stuck

Got a brand new distributor, starts up and idles amazing and, oh man does it ever sound so much better with a new exhaust manifold LoL

Go to throttle it up, and it begins to misfire, the faster and faster the worse it gets starving for gas, for giggles I spun the main jet out completely, tractor runs amazing from idle to wide open throttle. Well whatever I'll just plug the hole and see what happens, tractor leans out again. (What I should have done is drilled a tiny hole in the top of the carb and called it a day haha)

So I pull apart these two carbs and I cannot figure out what is really different about how they keep the pressure in the bowl at atmospheric pressure

I look the shafts and all the important parts the old one needed out of the new one and slapped it together

Tractor starts right up and idles fantastic
But now when I throttle it up it's running like the choke is on, not much but some black smoke and it will do this right up until the main jet and the idle mixture screw are shut off (the screen on the air cleaner is clean, oil bath cleaned and oil replaced) and even does this with the intake tube removed

Even more fun, he was addiment he had to use this thing even though I wasn't satisfied with it, he thought it was good enough for him so I put it together as is.

He got about 2 hours of use out of it before he was tired of how it ran.

Spark plug 1&2 are black as coal, 3&4 are perfect clean and drenched with gas

Ran a compression test and all holes are between 85 and 95 cold, 3&4 being both in the 90's

Put a much needed set of new wires on and a new set of plugs today. At idle it runs smooth on all 4, verified by removing one plug wire and reinstalling at a time

Anything above idle cylinder 3 has a slight misfire, 4 is totally dead

Makes me think there is a bit of a timing issue so I pull apart the new distributor and put a drill on the shaft and the flyweights seem to move in and out as they should.

So I reinstalled the distributor and lossened the screw to adjust the timing, pulled off the belt so I don't chop my fingers off, this thing ain't worth my fingers

Go to start it, starts right up and dies everytime I get to the front of the tractor now

I'm ready to send this thing over a cliff, and I know at first guess you would think I have wires 3&4 mixed around, I have checked and verified and verified again and switched them to backwards cause why not try hahaha

I know I wrote a book, I'm sorry, but information and understanding is good

Thanks for any thoughts or help
 
Hello jk, welcome to YT. This YT thread from a month or two back has a lot of info on your demise. In particular the linked posts in Dave G9N’s post. YT post on N aftermarket carbs It will probably run better if you clean the old one GOOD and put it back on loose throttle shafts or not. Not really a Ford guy so not sure how hard it is to re-bush them. It’s fairly late so I will tell you a secret about carbs like are found on these old tractors and many more applications. You mentioned about “keeping pressure in the bowl at atmospheric pressure” you were getting close to the secret. Look at the picture it is from another YT post I will link at the end. I added a squiggly red line that starts at the throttle plate and runs down a stops near the top of the removable main jet nozzle. Here it comes, guess what that passage does? Ever wonder why that nozzle has a series of holes in it? Bet you thought it was to make sure plenty of gas could get in there, wrong! That passage is feeding air down there to the outside of the nozzle where those holes are. There it mixes with the gas and “emulsifies” it so it is better able to vaporize into the air stream, that’s the secret. Often when a carb doesn’t work right and someone opens it back up and re-cleans it they get that passage unplugged and bingo they are back in business. Happy tractoring!
The post the carb diagram is from
 

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Not next to it at the moment, I did find that hole, both were in a similar location but both were drilled different and the casting around the hole is very different plus the the venture all together is rather pathetic at best.
Definitely getting a slight bit of vacuum in the bowl, like if you put your finger over the hole where the main jet adjustment hole you didn't feel any vacuum but things would go down hill at about 15 seconds after being plugged off
I did swap the meter tube or whatever you wanna call it cause I pulled that one out of the old carb it was absolutely filthy.
The new carb don't get me wrong is pathetic but many of the parts are interchangeable, I pulled both throttle shaft and choke shaft with butterflies out and put them in the old one, definitely cured much of the problem with shaft play and where the linkage meets the shaft. I used the new screws that hadn't been apart 900 times and gaskets, plus a really really nice brush kit that cleaned the old carb quite well
I'll clean up the old meter tube and see what happens. With my luck one of the drive tires will fall off haha

Anyone time these things while running by ear?
I get bench timing but something has to accommodate for the wear, this things get up and go got up and left sometime before I was born
 

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