Tractor won't start

I have a Husqvarna, YTH1542XP, Kawasaki FH430V and have been having various problems with it.
Here is the history: It would continue to run after turning the key off.

• I rebuilt the carb, no change.

• Replaced the carb and was really hard to start & it would stall.

• I replaced the spark plugs, coils, & fuel pump.

• Then it would start and would run about 15 minutes and stall as if it ran out of gas.

• Loosened the fuel cap with no change.

• I cleaned the carb and when I tried to start it, it would crank but then it wouldn't stop when I turned ignition key off and I had to disconnect negative battery cable to get it to stop.

• I replaced the solenoid & ignition switch.

• Now it cranks but won't start.

• Stator Coil resistance tests good.

Any ideas?

The engine not shutting off is a bad ignition switch.
Three things happen when you turn the ignition off
1) power supply to the fuel solenoid is cut = stops the engine
2) magneto is grounded = stops the engine
3) alternator is disconnected ( on some )


So your original problem was in the ignition switch .

Starter spinning all the time can be the ignition switch and can be the solenoid itself.

As you have done so much, thus introduced many potential problems we must take this one step at a time.
So we will start with the not starting.

Take the blower housing off , remove the kill wires and try to start the engine .
If it starts right up then you have a problem in the safety circuit.
Verify this by measuring the kill wire.
It should be open ( ignition on ) or ground ignition off.
If it is always open you have a problem with the ignition circuit.
There are 3 switches in the kill circuit, the ignition switch the PTO switch & the brake switch + the wires between them.
Because this is a ground circuit, there will be no indication of a bare wire shorting out other than no spark.

If the kill wire shows voltage the magneto coils will be dead as battery voltage fries the control chip embeded in the magneto coil.
If the kill wire shows voltage you might have the wrong ignition switch.

When we get this sorted we will worry about the cutting out.
However if it ends up being a bad switch or short that might be the only problem.

So do that then get back

Thank you for your help. Where are the kill wires? I've attached the schematics.

The kill wire(s) on the Tractor schematic is the one attached to the left side of the Ignition Unit labeled black/white in color. It connects to the M terminal on the Ign switch.

The kill wire on the Engine schematic is labeled "B" and you see it goes up to one of the coils and a jumper over to the other coil. It is connected to the "b" terminal on the Ign switch on this schematic.

In both cases, if you look at the table which shows what is connected to what in each key position, you'll note that the "kill" wire is connected to ground when the key is in the Off position.

Okay, so let me make sure I understand. Remove black/white (kill) wire going to the ignition unit & wire B going to the spark plugs or are they one & the same? See if it starts.

I don't understand when you say the kill wire should be open with the ignition on or the ground ignition off. Do you mean I should read infinity when the ignition switch is off and in the run position?

And, what do you mean by always open means a problem with the ignition circuit? If black/white wire reads infinity in the run position?

Those "kill" wires are grounded when you turn the ignition OFF. You remove them and that will 'allow' your engine to start. However, IF it starts, it will NOT stop unless they are reconnected. Said another way, when those ignition coils are grounded via the kill wire connected to ground(when key is in OFF position), NO SPARK is produced. So, when Berts suggests disconnecting them, that's how we determine where to head next. If engine starts and runs, we know the "kill" circuit is the problem. If the engine doesn't start, we suspect the Ign coils. Highly unlikely though that both Ign coils would be bad at the same time. Again, keep in mind that if you disconnect both and get the engine started, you'll have to ground both to get the engine to stop!

Make sense?

Yes, I understand that but trying to figure out what I need to do physically.
Do I remove black/white (kill) wire going to the ignition unit & wire B going to the spark plugs or are they one & the same? Then see if it starts.

Should it read infinity when the ignition switch is off and in the run position?

Is the black/white wire supposed to read infinity in the run position?

Did nothing & tried to start it. It started for a second and then died. I disconnected wire B (engine schematic) & tried to start it. Engine never turned over. What next? Thank you!

Ignore the Kawakasi diagram as they use a different numbering system and it will get confusing.
Because mower mechanics like me are only one step away from swinging in the trees & dragging our knuckles the mower companies make things simple
On the back of the ignition switch.
G = Ground
B = Battery
M = Magneto
S = Starter
A = Alternator
L = lights

Your magneto coils have 2 wires on them
1 thick one which goes to the spark plug
1 thin one which is the kill wire and goes to the M terminal on the switch
Because you have 2 magneto coils the thin wire goes from one coil to the other.
Sometimes this is a single wire and some times the coil has a second tab for the kill wire that connects both coils together.

AS there is no national standard wire colours are a bit hit & miss but it is the black & white wire in the Husky diagram .
when that wire, the small one on the coils is removed from both coils and you do a continuity test between the wire & ground you should see 0 ohms ignition off and infinity- over limit- out of range ( whatever your meter reads with the probes touching nothing ) with the ignition on.
If you don't get those readings the wires or the switch are bad.
With the thin wires on the coil removed the engine should crank and spark and hopefully run
Note you need to remove the blower housing and remove the wires at the coil, not just unplug at the joint outside the engine.

If you removed the B wire at the ignition switch then the switch gets no power so the engine can not crank.

If you are still lost take a nice clear photo of the top of your engine, blower housing removed and post it so we can mark it up for you.

Thank you, bertsmobile1. Continuity is there between wire & gnd with ignition off and infinity when ignition is in run position.