1941 9N Will Only Run with Starter Engaged (12V)

cquayle77

New User
I have a 1941 9N (12V) that currently will only run (Produce spark) if the starter motor is engaged. It has been running perfectly for the past few months, and then the other day, about an hour after using it, it suddenly would not run unless the starter was engaged. I have tested the battery, bypassed the key switch, and the resistor, and have even tried running a wire directly from the battery to the coil, but with no luck. There is constant power to the coil, as long as the key is turned, but for some reason the spark plugs quit sparking as soon as the starter button is released. It produces good spark when starting, but dies immediately after. I've have done what other related posts suggested, but still can not get it running. Please help!
 
Your testing or observation procedures must be at fault.

If you have run a direct wire from the battery to coil top, and if the starter is engaged it has spark, but spins down with no spark when you let up, you pretty much have a fault in observation.

Re check your wiring.

Re check where you are getting ignition power from.

Can we guess that you have a key, turn to start setup, and have power to the coil only in the start position part of the key, and don't have run hooked to the coil? ( or switch failed? )

Post back
 
I have re checked the wiring 2 or 3 times now, with no success.
There is a push button that directly runs the starter motor when pushed, and then an on/off key switch, that when on, provides the coil with power.
 
Do a compression test.

She has to turn to make spark.

It may be that she can't sustain running without starter assistance. You may be running on 1 cyl, have stuck open valves, or other ultra low compression issues.
 
I don't think that compression is the problem. It starts just like it is supposed to, and will even run when I pull the throttle down, as long as I have the starter button pressed. However, as soon as I release the button it quits. I have tried taking the plugs out and checking them for spark, and all 4 have strong spark when it's turning over; but as soon as I release the button, the plugs stop sparking. There's no residual spark as the engine slows down. It's as if the push button starter is acting as the key switch, but I followed the wiring diagram correctly, and the push button has nothing to do with the power to the coil.
 
If the wire that goes from the starter switch to the terminal block and supplies power to the ignition switch is on the wrong side of the starter switch it will act as you describe. That wire should be on the same side as the cable to the battery, not the side with the cable to the starter.

I've seen that happen more than once.
 
Where is your ground wire connected? If you have power going to the coil and no fire it would seem as though you have a ground problem. If the ground wire is connected to the starter it could be that the block is only getting ground when the starter is engaged. Try connecting a jumper cable from the negative battery post to a ground on the engine block.

Mark
 
Before you start buying any new parts and replacing, if part condition is unknown, changing it is only further adding to the problem. It sounds to me like your wiring is all jazzed up. Yes, I know you said you have a 12V system, and you have checked the wiring, but, that means nothing. How did you 'check' the wiring? With a correct 12V wiring diagram? We need to know exactly every detail of the electrical setup, especially how it is wired. We will assume because you said it is a 1941 9N, it has the front mount distributor -or has EI been added? We also assume you have a 12V battery but really that's all we know. Here are mine and I'm sure some other's questions: Front mount distributor, and how old are points? 1-Wire Starter -NO SOLENOID? 1 or 3 Wire Alternator? 6 or 12 Volt coil? OEM Ballast Resistor in place and wired as original? You need that regardless if using a 6V or 12V coil. If using a 6V coil, is the external 1-OHM ceramic resistor in the circuit? Has the cutout circuit been removed altogether? Has the key switch been left on, engine not running, for an extended period of time, say overnight?

TPD
 
Does your 12 volt conversion add a starter solenoid? One like a G.M. solenoid that has a start circuit and a run circuit maybe?
 
I just tried using a jumper cable to create a better ground, but it still wouldn't start.
My tractor has a front mount distributor, with an electronic ignition instead of points. There is no solenoid, other than the push button starter, which I've heard be referred to as a solenoid before. I have a 3-wire alternator, and a 12v coil. There is a ballast resistor in place, and the key is always off when I'm done using it. Here is a picture of the wiring diagram I used:
mvphoto20920.jpg
 
I must admit I don't have much experience with electronic ignition but since it was running and quit the wiring must be correct and something has changed to make it only spark while cranking. The next thing I would do is clean all the connections at the battery and starter button all the way to the distributor paying special attention to the red wire and it's connections.

Mark
 
The electronic ignition was the problem. I just replaced it with the old points, and it started up and ran perfectly!
 

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