Aftermarket coils

[Tinkerer200]

Thanks, Walt,

Engine: 446777-0316-E1 - Briggs & Stratton V-Twin
Mower: MTD 14AR808K731 - Huskee Garden Tractor (2004)

My rudimentary understanding of electricity tells me that, if the kill wire to one coil is grounding out,that both coils would shut down.
That should be true unless the engine has kill wires that are independent and isolated for each coil.

Am I incorrect?

Ever hear of diodes? I don't think you understand the B&S twin Kill Wire system.

Walt Conner

 

[Ronno6]

Ever hear of diodes? I don't think you understand the B&S twin Kill Wire system.

Walt Conner

Yes,I have.
Apparently you are correct.
Please elaborate...........

 

[Boudreaux In Eunice La.]

Well, after cleaning all points of contact and re-installing the suspect coil, the motor
ran fine until yesterday. One cylinder dropped out while mowing, but came back a short time later.
So, it worked perfectly-til it didn't.
Then, it didn't-til it did.
Sounds kinds like the makings of some sort of nursery rhyme...

I purchased 2 B&S modules, so I guess the time is nigh to install them..........

Did you install the new coils yet ??

 

[Boudreaux In Eunice La.]

Ronno............ I am awaiting your answer on the coils, but I will say a couple things about a diode.

1st.... If a diode is bad then it's bad. No intermediate on that.

2nd.... Have you ever hooked a car stereo up backwards and saw a puff of smoke ??? If you did you blew the protective diode that keeps the radio from being totality fried. 2 things could happen with that diode, it is open like blown fuse would and when you try to hook the radio back up again the right way it won't light up or work..... Or the diode shorted and it will still smoke when you try to hook it back up the right way again.

I had a two way communications repair and sales shop in the late 80's and most of the 90's.... I have replaced more of those diodes than I can count on a calculator LOL. Cheap too, 2 to 3 cents apiece and a total bill bill of 15 to 25 bux for the parts and labor............. Depended on if I had to fix a tracer or change fried wires going to the plug in for 12 volts....

 

[Ronno6]

Did you install the new coils yet ??

Ahh, the P-N junction.....the building block that is the very basis of all things solid state..........

No, I have not as of yet installed the new modules.

It may be relevant at this point to relay that, during the one period of apparent coil failure
that was of sufficient endurance that I could see that there was no spark on the #1 cylinder,
I disconnected the kill wire from the #1 coil, and there was still no spark.
After removing the coil, cleaning the contact points of the coil armature and re-installing the coil,
there was again spark.
Hence I did not suspect the kill wire circuit.

Unless, there is a coincidence going on here..............

p.s. I am typically in bed by 10................

 

[Ronno6]

This diagram shows the 2 diodes in the kill wire circuit:
https://www.vanguardengines.com/con...s/Files/FAQs/ignition_wiring_6_pin_ms5301.pdf

So, in essence, the 2 coil kill wires ARE isolated in the reverse direction....
Shorting one kill wire to the block between the diode and the coil will kill only that coil.

It is interesting to note that I have yet to see these diodes in any electrical schematics.

 

[Tinkerer200]

Ronno............ I am awaiting your answer on the coils, but I will say a couple things about a diode.

1st.... If a diode is bad then it's bad. No intermediate on that.

2nd.... Have you ever hooked a car stereo up backwards and saw a puff of smoke ??? If you did you blew the protective diode that keeps the radio from being totality fried. 2 things could happen with that diode, it is open like blown fuse would and when you try to hook the radio back up again the right way it won't light up or work..... Or the diode shorted and it will still smoke when you try to hook it back up the right way again.

I had a two way communications repair and sales shop in the late 80's and most of the 90's.... I have replaced more of those diodes than I can count on a calculator LOL. Cheap too, 2 to 3 cents apiece and a total bill bill of 15 to 25 bux for the parts and labor............. Depended on if I had to fix a tracer or change fried wires going to the plug in for 12 volts....

While you may be an expert with car stereos, I can assure you the small engine forums are full of mysterious symptoms caused by the B&S twin kill wire system, several times as many as by the coil. OP did not originally furnish the information that he had disconnected the kill wire from dead cylinder coil. Note that he may have solved his problem by following my first advice.

Walt Conner

 

[Boudreaux In Eunice La.]

Tinker I was not telling him how to fix his problem because of a diode. He wan't to know about how a diode worked.

By the way he fixed his problem. It was a bad coil so he got 2 new ones to put on there.

 

[Tinkerer200]

Tinker I was not telling him how to fix his problem because of a diode. He wan't to know about how a diode worked.

By the way he fixed his problem. It was a bad coil so he got 2 new ones to put on there.

The post where he says he installed the new coils is missing from the thread I get.

Walt Conner

 

[Boudreaux In Eunice La.]

We talked off of the forum. Too much typing for the conversation we had.....