Craftsman dyt 4000 lawn tractor not getting any spark Help please

[mrbreezeet1]

My buddy has a Craftsman dyt 4000 lawn tractor he wasn't getting any spark. He bought a new coil from eBay or Amazon and installed it in the tractor and, the engine started right up, but when he put everything back together, the covers and everything it wouldn't start any more. so he tried another coil............. same thing ran for a while put the covers all back on now it won't start. (He did set the "air Gap" between the coil and the flywheel each time he installed the coils) I assumed we should have battery voltage to the wire that plugs on to the coil of a Craftsman DYT 4000 lawn tractor, but I must have this wrong, because I see the tab for the electrical plug provided keeps being referred to as a "Kill wire connection" So does this system need battery voltage to the coil to start and run, I am also going to have him test the old coil, and the two "new coils" he installed. Now unless the old coil was bad, and the two new coils are junk too, and failed to work after they were hot.

 

[Elkins45]

The wire to the coil is a ground that kills the engine when the mower is switched off. If reinstalling the covers makes it not run then my first guess is there’s a short between the covers and the wire somewhere. Look over the length of the wire and look for a gap in the insulation where it touches metal.

 

[mrbreezeet1]

OK Thanks! I'll have him do that tomorrow. I am trying to help him over the phone. He's pretty sharp too though.
He did not see any indication of pinching the wire. But I'll have him double check tomorrow.
I was going to have him install one of the new coils again, but this time leaving the kill wire off,
(just to be double sure the wire is not shorted somewhere.) and see if we get any fire.
If still no spark, it almost has to be a shorted or bad coil then right?

 

[fantastic]

Try a new plug?

 

[mk378]

Leaving the wire off would be a good test. When the kill circuit is open, the engine can run. Turning the key off connects it to ground, killing the sparks. This type of ignition system is self-powered and doesn't use 12 volts from the battery at all.

On a riding mower, various interlocks such as leaving the seat with the blade engaged will also ground the wire to kill the engine. This may be wired directly or through relays that use battery power.

 

[97prizm]

My buddy has a Craftsman dyt 4000 lawn tractor he wasn't getting any spark. He bought a new coil from eBay or Amazon and installed it in the tractor and, the engine started right up, but when he put everything back together, the covers and everything it wouldn't start any more. so he tried another coil............. same thing ran for a while put the covers all back on now it won't start. (He did set the "air Gap" between the coil and the flywheel each time he installed the coils) I assumed we should have battery voltage to the wire that plugs on to the coil of a Craftsman DYT 4000 lawn tractor, but I must have this wrong, because I see the tab for the electrical plug provided keeps being referred to as a "Kill wire connection" So does this system need battery voltage to the coil to start and run, I am also going to have him test the old coil, and the two "new coils" he installed. Now unless the old coil was bad, and the two new coils are junk too, and failed to work after they were hot.

Check for a safety switch on the sear. I've seen them go bad and cause Similar issues.

 

[mrbreezeet1]

Try a new plug?

Yes, He got a new plug too.

 

[mrbreezeet1]

Leaving the wire off would be a good test. When the kill circuit is open, the engine can run. Turning the key off connects it to ground, killing the sparks. This type of ignition system is self-powered and doesn't use 12 volts from the battery at all.

On a riding mower, various interlocks such as leaving the seat with the blade engaged will also ground the wire to kill the engine. This may be wired directly or through relays that use battery power.

OK, I understand. I will follow up.

 

[mrbreezeet1]

Check for a safety switch on the sear. I've seen them go bad and cause Similar issues.

OK Thank You. Yeah the seat. I'll have to look for a wiring diagram if there are more than two wires on the seat safety switch.

 

[chemman]

Regarding the interlock safety switches - I too own a Craftsman DYT 4000 lawn tractor and had a strange electrical problem - mower ran fine until I put it in gear and released the brake.

I checked all the interlock switches - all were good. I checked the wiring point to point - all good. However, when I used my analog VOM and looked at the entire circuit, there was some moving around of the VOM's needle. Turns out there was a few ohms of resistance in the entire circuit which was enough to cause the mower to die.

Long story short - problem turned out to be small resistances at the crimps between the wire and each terminal connector due to corrosion (green grunge). Replaced the crimp on connectors and soldered them after crimping them, and spraying some contact cleaner in all the switches to clean the internal contacts. End result, zero ohms in the entire circuit, steady VOM meter movement needle, and the mower ran as it should.

As far as the wiring diagram goes, you need to get the 9 digit model number (e.g. 917.275123) from the mower, go to www.searspartsdirect.com, enter the model number, then select models, and the page comes up with a link to the owner's manual which should have the wiring schematic in it.

Good Luck!

 

[mrbreezeet1]

Check for a safety switch on the sear. I've seen them go bad and cause Similar issues.

Thank You, OK, I understand. I will follow up. He didn't have time to try or test anything today.

Regarding the interlock safety switches - I too own a Craftsman DYT 4000 lawn tractor and had a strange electrical problem - mower ran fine until I put it in gear and released the brake.

I checked all the interlock switches - all were good. I checked the wiring point to point - all good. However, when I used my analog VOM and looked at the entire circuit, there was some moving around of the VOM's needle. Turns out there was a few ohms of resistance in the entire circuit which was enough to cause the mower to die.

Long story short - problem turned out to be small resistances at the crimps between the wire and each terminal connector due to corrosion (green grunge). Replaced the crimp on connectors and soldered them after crimping them, and spraying some contact cleaner in all the switches to clean the internal contacts. End result, zero ohms in the entire circuit, steady VOM meter movement needle, and the mower ran as it should.

As far as the wiring diagram goes, you need to get the 9 digit model number (e.g. 917.275123) from the mower, go to www.searspartsdirect.com, enter the model number, then select models, and the page comes up with a link to the owner's manual which should have the wiring schematic in it.

Good Luck!

Oh good job!
Sorry l must have missed this, yes l have the model number, Thank you.

 

[mrbreezeet1]

Leaving the wire off would be a good test. When the kill circuit is open, the engine can run. Turning the key off connects it to ground, killing the sparks. This type of ignition system is self-powered and doesn't use 12 volts from the battery at all.

On a riding mower, various interlocks such as leaving the seat with the blade engaged will also ground the wire to kill the engine. This may be wired directly or through relays that use battery power.

Well he tried leaving the kill wire off, on at least 2 of the coils, the old original one, and one of the ebay coils, no joy/no start.
I can't see anything else but the coil itself.
Can You? We did check with multi meter between the kill tab and the coil lead, was supposed to be IIRC no more than 2K resistance, but he was getting between 5K and 6K reading on all the coils,
I don't know what the heck else it could be, but the coil it self.
What the heck is burning these coils up, besides just junk coils? Should he get a new one somewhere else?What is the best one to get if that is the case?

 

[chemman]

Since I do not know what engine is in your friend's DYT 4000 mower, I would advise to purchase an OEM coil or one from Stens, Rotary or Oregon (decent aftermarket brands) and install it.

I hesitate to purchase no name parts like that from anyone (internet sellers or brick and mortar shops) because I do not need for the part to be DOA, be marginal in how it works, or become defective shortly after installation. I have purchased a number of OEM B&S parts from www.equipatron.com and have found them to be less expensive than purchasing the same parts from www.jackssmallengines.com or www.rcpw.com.

 

[mrbreezeet1]

Since I do not know what engine is in your friend's DYT 4000 mower

Sorry, Briggs and Stratton 18.5 HP Thank You!

 

[chemman]

OK, likely the same engine as the one on mine. I would go with a B&S 591459 Armature-Magneto ("ignition coil"), a Stens 520-441, or a Rotary 9293.

Just as an FYI, Equipatron sells the B&S OEM part for $40.55 (plus shipping) and Amazon sells the Stens part for $40.89. Also, Amazon is currently selling the B&S coil for $37.22, and the Rotary 9293 coil for $33.47.

Good Luck!

 

[mrbreezeet1]

OK, likely the same engine as the one on mine. I would go with a B&S 591459 Armature-Magneto ("ignition coil"), a Stens 520-441, or a Rotary 9293.

Just as an FYI, Equipatron sells the B&S OEM part for $40.55 (plus shipping) and Amazon sells the Stens part for $40.89. Also, Amazon is currently selling the B&S coil for $37.22, and the Rotary 9293 coil for $33.47.

Good Luck!

That's not too bad price wise, I told him to try to open a case with ebay to get his money back on those 2 coils.
So I take it, you agree it can't be anything but the coil itself. (That's what I told him)
Thanks a million!

 

[mrbreezeet1]

OK, likely the same engine as the one on mine. I would go with a B&S 591459 Armature-Magneto ("ignition coil"), a Stens 520-441, or a Rotary 9293.

Just as an FYI, Equipatron sells the B&S OEM part for $40.55 (plus shipping) and Amazon sells the Stens part for $40.89. Also, Amazon is currently selling the B&S coil for $37.22, and the Rotary 9293 coil for $33.47.

Good Luck!

That Stens is coming up on Google as a fuel pump?
https://www.google.com/search?client=firefox-b-1-d&q=Stens+520-441
But I forwarded your reply to him.

 

[chemman]

Sorry about the Stens mix-up. The correct Stens part number is 440-433. The part price is for the magneto, however.

In my vehicle/OPE spreadsheet that I use to log maintenance/repairs, I also have a section with common repair parts part numbers and brands for each vehicle/ piece of equipment. For the DYT-4000, fuel pump information is right above the Armature-Magneto/Ignition Coil part information.

So, if your friend ever needs a fuel pump, he already has the part number.

 

[mrbreezeet1]

Thank you

 

[chemman]

You are quite welcome!