1949 8N Won't Start

[UpLateAgain]

My engine rebuilder told me it was very common on those old Ford Model A engines for valves to suddenly decide to stick open. If that's what is happening with your tractor, you should be able to tell by doing a compression test. If you get cylinders that are showing little or no compression, you'll probably have to pull the head and physically check how each valve is seating. He said often simply tapping the valve head lightly with a hammer will free it, and you may never again have the problem, (though he did recommend replacing a quart of oil with a quart of Marvel Mystery oil for one oil change if you find a sticking valve or two). And if it is a sticky valve, you may get a sticky valve to free up just by tapping the side of the block where the valves are with a hammer several times. Just don't hit it hard enough to crack the block.

 

[Bartman1959]

IT'S ALIVE!!! I bypassed the ceramic resistor, put a full charge on the battery, and it fired right up. I let it run for about 10 minutes increasing and decreasing throttle, and it ran great. I turned it off for a couple of minutes, then restarted it and let it run for a few minutes, then shut it off again. I did that several times and it worked perfectly every time.

Thanks Soundguy for all your help, and thanks everyone else for your input.

 

[jaxs]

:scratchchin: All is well that end's well. :cool2:

 

[Phillip w]

IT'S ALIVE!!! I bypassed the ceramic resistor, put a full charge on the battery, and it fired right up. I let it run for about 10 minutes increasing and decreasing throttle, and it ran great. I turned it off for a couple of minutes, then restarted it and let it run for a few minutes, then shut it off again. I did that several times and it worked perfectly every time.

Thanks Soundguy for all your help, and thanks everyone else for your input.

If you are running, good chance that ballast resister is bad. It will run like this "in a pinch", but I am pretty sure need to replace that resister. Running with the resister bypassed is hard on the coil and can end up blowing the coil. At least that is the way the old dodge were. Maybe soundguy Will post his thought on the matter and we'll get his perspective.

 

[Soundguy]

No, he had too much resistance. He bypassed the ceramic resistor leaving the ballast resistor inline.

At some point someone converted that machine to 12v, and kept the 6v coil and added the ceramic resistor, then later put a 12v coil on and didn't remove the resistor like they should have .

With the ceramic resistor out of circuit, and ballast resistor in circuit, its fine.

 

[Soundguy]

My engine rebuilder told me it was very common on those old Ford Model A engines for valves to suddenly decide to stick open. If that's what is happening with your tractor, you should be able to tell by doing a compression test. If you get cylinders that are showing little or no compression, you'll probably have to pull the head and physically check how each valve is seating. He said often simply tapping the valve head lightly with a hammer will free it, and you may never again have the problem, (though he did recommend replacing a quart of oil with a quart of Marvel Mystery oil for one oil change if you find a sticking valve or two). And if it is a sticky valve, you may get a sticky valve to free up just by tapping the side of the block where the valves are with a hammer several times. Just don't hit it hard enough to crack the block.

It would be way more advisable to pull the valve covers than going straight for the head. People are usually too quick to pull heads when it may not be needed.

You can access the stems and usually free up stuck, undamaged valves from the covers with a minimum of work. ATF, acetone and a toothbrush will do wonders .

 

[Bartman1959]

Again Soundguy, thanks for all your help.

 

[mapper]

It would be way more advisable to pull the valve covers than going straight for the head. People are usually too quick to pull heads when it may not be needed.

You can access the stems and usually free up stuck, undamaged valves from the covers with a minimum of work. ATF, acetone and a toothbrush will do wonders .

Good advice, not much room above the head without removing the hood and gas tank!

 

[Bartman1959]

The way it's running right now, I don't think I need to pull anything else off the tractor. If it starts to run bad, I'll look at the valves then.

 

[Bartman1959]

I think it's time to clean up my shop a bit and get my 1948 Ford F-1 in there and get started on it. That is my winter project.