Engine not shutting down when key tuned off

This is not a run on question (from carbon in the engine) Working on an Ingersoll 224 lawn tractor. Had to fully rewire the 12 volt side from key to solenoid to coil and generator/ starter. [ all original wires junk] NOW starts ok but when I turn the key to off the engine keeps running. Went over the wiring diagram for this tractor [even enlarging it to see all components] The only item I have noticed is a { block } on the line from the B terminal on the voltage reg., to the battery side of the solenoid. Can't figure out if it is a junction or a diode.

????So QUESTION ???? what have I missed that is allowing the engine to continue to run when the key is turned to off position? (( by the way asked this on the lawn tractor portion of the forum / no answer)) To stop the engine have had to pull off the spark plug wire.
Thank you for all your assistance.
Wm.

My first guess is that there is a fuel shutoff solenoid that is remaining energized. If you have such a device, it would be located on the carburetor. To check, it should have voltage to it when the key is on and not when the key is off.

My second guess is the kill circuit. When you turn the key to the off position, it should ground the kill wire coming from the ignition module or magneto. If you have a small wire coming out of the ignition assembly, that should be the kill wire. Grounding it should stop the engine.

Those are my educated guesses. I have no experience specific to the model you are working onso I can't tell you "chapter and verse" how it should be wired or how it was originally wired. Only offer generic advice frompast experience.

Good luck.

Thank you for your thoughts. The carb is a standard old style, had it apart to clean it, it has no electrical components.
The key switch is a standard 4 poll type with start in the center, and 3 around the out side Ignition, AC., Battery.
As I said when the key is turned to off the coil is still receiving power. Unable to figure out what I missed. As I said even enlarged the wiring diagram to see it more clearly to try to be as certain as possible to connect the wires to the proper pols.
Wm.

Is the ignition magneto or battery?

If it's battery, possibly there is a back feed keeping power to the coil.

Being a generator, I don't see it having a diode or resistor involved in the charging system. If there is a charge light, there will be an output signal to supply the light with power to give it double positive signal. Possibly that could have been miswired.

When you stopped it by pulling the plug wire, did you check for battery drain?

If it is magneto, there will be a separate section of the ignition switch that grounds the coil to kill it. If the ignition switch was replaced, was the correct switch used?

All just guess work and assumptions, don't hold it against me!

(quoted from post at 12:21:22 03/06/21) Is the ignition magneto or battery?

If it's battery, possibly there is a back feed keeping power to the coil.

Being a generator, I don't see it having a diode or resistor involved in the charging system. If there is a charge light, there will be an output signal to supply the light with power to give it double positive signal. Possibly that could have been miswired.

When you stopped it by pulling the plug wire, did you check for battery drain?

If it is magneto, there will be a separate section of the ignition switch that grounds the coil to kill it. If the ignition switch was replaced, was the correct switch used?

All just guess work and assumptions, don't hold it against me!

Click to expand...

'm with jimg & Steve, on needs ground to mag to kill spark.

I haven't worked on a 224 but my guess is that the spark is produced by a magneto and when you turn the key to off, it does not ground it. Can you try sticking another wire from the pole on the key that goes to the magneto and ground the other end of that wire to the engine block to see if that kills it?

This is a points, coil, capacitor, high tension system. As far as I can tell I have followed the wiring diagram carefully as I put new wires on the 12 volt side. The only thing I can think of is that the key switch is now working correctly. Yet does that make sense? Or is the wiring diagram from key to coil or solenoid or starter not fully correct? I am not able to make sense of this for the obvious thing is there must be a power feed that is not disconnecting.
What about a faulty key switch? Does the key switch go to ground when the key goes to off? I have attempted to look for a simplified diagram of standard key switch with center start poll and 3 lug around the out side and wired to coil, starter, and coil haven't found one yet; there must be one out there some where. I know there is a simple answer; yet this is simply not making sense.
Wm.

One terminal of your key switch should be connected to power source (hot wire from battery or wherever). There should be no power at the other terminal(s) when in the "off" position--only when in the "on" position. Without seeing your switch I can't be any more specific than that. But that should give you a starting point. Presumably the terminals would be labeled as to which is which. Hope that helps.

Well thank you to all. I was on line looking at issues with switches. One person wrote that he was having the following issue; the switch was starting the engine even when just turned from off to run position. it took him several attempts to figure it out but discovered that the internal parts when the ugs were tightened , cased the internal parts to short causing the engine to start in just on position. ""SO"" this, plus all your suggestions gave me the idea to check the switch with a meter in start, run and see if when I turn it to off if the switch is still registering on. //By the way reprinted the wiring diagram in much enlarged printing. Will also go over the wires by wire to make certain each is in proper place also, and there is no crossed wire leading to power track keeping the power to the spark plug.//
Thank you again. Will send an update as to what I find.
Wm.

Since you have a battery/points/coil ignition, that raises some new possibilities.

Since you have a more automotive type of ignition, there are also other automotive type features that would have come along with that. Electric starting, a charging system, and a battery to run it all. There would also be accessories that would run off the electrical system like headlights, PTO, and maybe even a horn or cigarette lighter.

with a more complex electrical system, your ignition switch should have taps for ignition system, accessories, and starting. If your ignition and accessory circuits are on the same tap on your switch, you need a means to isolate the charging circuit from the ignition circuit or the charging system will feed back to the ignition system and cause it to remain energized after you turn the switch off.

To isolate, you need either to separate the ignition system from the rest of the electrical system by either putting it on a different tap on the ignition switch or installing an isolation diode to prevent the charging system from back feeding the ignition.

To test this, with the engine running, check for voltage at the battery side of the coil. Then turn off the switch. If the voltage does not drop, it tells you that something is back feeding the ignition. That is where the problem will be found.

One thing I have found is that there are any number of different ignition switch configurations. The switches look the same but are wired differently internally.

Thank you Jim G I will do testing this week I have done all the checking and re checking on the layout of wires to do my best to remove any wrong connections. So far I can find no wrong connections. So I do think that a a diode is most likely the solution. It will need to be a high wattage one, so I will search one out and install in the line from post 4 on the V/R to the battery side of the solenoid [ on the wiring diagram thee was a 'fixture' that I couldn't identify maybe it was a diode.
At least this is a start to figuring out the problem. I have printed your information to go over it at the tractor.
Thank you again for your assistance. Shall let you know what I find out.
Wm.