Engine 2 replaced magnetos (ignition modules) on rider mower.

[wetweasel]

I have a craftsman rider (model 31p7770348e1). Recently my craftsman would not start and I was getting no spark. Diagnosed down to the magneto and replaced. The mower started once and then no spark. I disconnected the kill and still no spark. so... I replaced the magneto again. Onc again it started and ran but then would not restart. Same problem... I changed spark plug as well... What would kill two new magnetos? I don't want to kill another?

 

[reynoldston]

I have a craftsman rider (model 31p7770348e1). Recently my craftsman would not start and I was getting no spark. Diagnosed down to the magneto and replaced. The mower started once and then no spark. I disconnected the kill and still no spark. so... I replaced the magneto again. Onc again it started and ran but then would not restart. Same problem... I changed spark plug as well... What would kill two new magnetos? I don't want to kill another?

Positive voltage to them.

 

[wetweasel]

Positive voltage to them.

yep... thank you

 

[hrdman2luv]

Positive voltage to them.

Please explain in detail. Because I'm having the same problem. I just bought my 3rd magneto.

 

[reynoldston]

Please explain in detail. Because I'm having the same problem. I just bought my 3rd magneto.

I order for the coil to operate you want no type of voltage to the primary wire (small wire) positive or negative. Now to stop the engine from running you will need negative voltage to the primary wire. If at any time you do get positive voltage to the primary side you will cause a short in the coil and can burn it up.

 

[reynoldston]

Another thing is what are you using for coils. A good OEM coil or a aftermarket Chinese junk??

 

[hrdman2luv]

I order for the coil to operate you want no type of voltage to the primary wire (small wire) positive or negative. Now to stop the engine from running you will need negative voltage to the primary wire. If at any time you do get positive voltage to the primary side you will cause a short in the coil and can burn it up.

So you're talking about getting voltage back up the kill wire to the magneto... What could cause this? It started and ran fine today (19.5 opposed twin briggs)
But after I killed it, it wouldn't get spark. While holding the plug against something grounded, it didn't spark most of the time. But when it did, it would spark a lot.

A couple of weeks ago, when this first started, it seemed to cut out when I hit bumps. That's when it died and wouldn't crank back up.

When it does crank & run, it cranks & runs greats. But, it's sporadic as to when it cranks & runs.

 

[hrdman2luv]

Another thing is what are you using for coils. A good OEM coil or a aftermarket Chinese junk??

The first one was from a briggs dealer, Came in a briggs box. The next one I got from Ebay, was the same kind. (only a lot cheaper) I noticed it's different than the one I took off originally.

 

[Rivets]

Hrs an, it sounds to me like you have a kill wire which is shorting out to ground. Check the entire length of the kill wire, looking for areas which are either pinched or rubbed bare.

 

[hrdman2luv]

Hrs an, it sounds to me like you have a kill wire which is shorting out to ground. Check the entire length of the kill wire, looking for areas which are either pinched or rubbed bare.

Even with then kill wire disconnected, many times I'm not getting spark to the plugs.