Another No Spark riding mower thread

[StumpyOrson]

I've got an old MTD Yardmachines that is as old as dirt and twice as ugly, but she cuts the lawn so she'd good enough for me. However, I hooked her up to a jump start battery the other day to start her.and instead of starting up and running like normal, she started smoking.
The battery connection wire runs from the battery, to what I assume is a little solenoid that is key operated, then splits off to the starter, a red wire that turns black before going to the key switch, and an orange wire with a black stripe that I didn't trace. The red wire that turns black is the problem. It doesn't connect to the solenoid, but comes out of the same spot that the red battery wire goes into.
That little wire plumb fried. Insulation burned clean off, stuck to other wires, etc.

So I pulled that wire and replaced it, but now I have no spark. What I'd like to do is:
1. get the motor started regardless of what it takes. If I can figure out which wire goes to all the various kill switches I'd like to remove it altogether and see if my spark returns.
2. figure out what the burned up wire is. Is it a charging wire maybe? I don't know, but as of right now it still starts to get hot when I have the key in "run", not "Start". When it starts, the key and wires seem to operate normally (except for no spark).

I've got all the time in the world to fix my old girl so if anyone has any tips I'll do what's necessary to get her troubleshot and running again.

Pics:

Here's the little solenoid with the burned red/black wire




The only four wires that come off the engine. Is one of these the master wire to the various kill switches? (Clutch, reverse, seat, etc)




Engine model, it's a 14.5hp IC Quiet




One of the plugs above runs to the fuel bowl. That seems weird to me.





Thanks in advance!

 

[Scrubcadet10]

The plug that runs to the carb bowl is the "Anti After fire valve" to prevent fuel from bring drawn into the cylinder after the key has been shutoff.
Most likely you have no spark because voltage got to the ignition coil and fried it, OR insulation was melted off the coil kill wire and it is now shorted to ground and causing the coil to not produce spark. Quick way to check is to unplug the kill wire from the coil and see if you've got spark. If you do with the wire unplugged the wire is shorted to ground or a key switch issue.
If you unplug the wire and still no spark , the coil is dead. BUT before you buy a new coil and put it on, you need to check to be sure there is no voltage on that kill wire. Any amount will fry the new coil.
The two sides that come from under neath the housing are most likely wires coming from the Stator (alternator).

 

[StumpyOrson]

Great thanks! So being specific, the kill wire is a wire from the coil to....the key switch? Is it the black wire coming from the coil? Can you see the kill wire in one of my pictures and say "Here's your kill wire right 'chere, boy. Now trace that down"?

 

[Scrubcadet10]

You'll have to remove the red blower housing off the engine to unplug it from the coil.

 

[Hammermechanicman]

The burned red wire looks to have been spliced into a black wire. If the wire smoked when you turned the key to engage the starter then the ground from the battery to the engine is bad.

 

[Scrubcadet10]

Also post up the model number of the tractor, being an MTD it should be underneath the seat on a tag. if it's still there.And also the engine model number, should be stamped right above the spark plug into the blower housing.
Model and Type #'s

 

[StumpyOrson]

Thanks guys. I'll get the cover off today. The motor model is 287707. The tractor model is long gone, but it looks exactly like this one here just in blue color.

Yard Machine Mtd 42 " Mower

Yard Machine Mtd 42

twentywheels.com

 

[StumpyOrson]

Well I got the cover off and one of the wires runs to the coil. Would that be the kill switch? I've also got a red and black wire that disappears underneath the um...spinny top of the engine..
New coil doesn't fit. Ordering another. Any other ideas?

 

[Scrubcadet10]

Unplug the 1 wire that is going to the coil. Try to start. If it has spark with that wire unplugged. It is either shorted to ground or there is a problem with the key switch.

 

[Scrubcadet10]

The wire that goes under the flywheel is most likely the Stator (alternator) wire.