Export thread

:confused2: Just wanted to run this past some of the repair guys. Had no spark, troubleshoot and find that my old 8 year old magneto on my 19 hp craftsman B&S failed; that was three weeks ago. Ordered a new one which wasn't cheap. ... tested it and I had spark. Alls good. Mowed my 1 acre lot no problems three weeks ago.

Grass hasn't really grown but thought I would mow it today and the engine turns over but doesn't start. I test out the spark and .. no spark. I take off the ground/kill wire on the magneto and still no spark. I'm hesitant to think its the magneto so I drive into town.. about 7 miles and pick up both a new spark plug and a spark tester. put that on and still nothing which leads me to the magneto again. Anyone see these units die? The small engine guy warned me that lately they flipped all the magneto wiring so it looks backwards when you install it but mine wasn't. Said which way to install on the magneto... not to mention it did work. But I'm wondering if parts like this go bad? I hate to order another $47 dollar part and have that go bad before I know if its just doa or something blow'n the unit. Any ideas? Bastards where I ordered it said they have no warranty on electronic parts....

Anyone know if you can ohm out the magneto to see if the windings are bad?
Any way to put a meter on the spark output to see if there is a voltage? or good voltage?

grrrrrrrrr........... working on the tractor twice in one month is not the norm. this craftsman has been a pretty good runner.

No, the bad news is that you likely have a problem that is sending voltage to the little wire going to your coil, and that will destroy it. If it didn't happen immediately, then it must not be a full 12 volts.

But on these engines, if you leave that little "kill" wire disconnected, then every time the flywheel rotates, you will have a spark. If you don't, then the coil is bad.

So if that is the case now, then your new coil is "toast"....

whats the best way to test that wire? connect my multi meter to it and turn over the engine? I tried that and only seen 200 mv. which is pretty small?

Unplug it and hook it up to your voltmeter and look for any voltage,

If you buy a new coil, do not plug in that wire!!!!

Check d.c. voltage first, then a.c......

checked both... both in the mv. range. maybe .5 on the AC but that was pushing it. Any other ideas? Else I'm going to the sears part store online...

You need to work the keyswitch, all of the other switches, wiggle/move/jostle the wiring harness around, and find out what is "killing" the coils.

Unless, you are not testing the coil correctly, which we have no way to know if you are doing that.....

eire said:

checked both... both in the mv. range. maybe .5 on the AC but that was pushing it. Any other ideas? Else I'm going to the sears part store online...

Click to expand...

Yeah, them sears boys are goooood.....

Ordered a new magneto and the new unit works. started the engine. Here's a question.. The B&S has a Fuel shut off solenoid on the Carb bowl... why? whats the purpose of that? I noticed mine might be a problem when the tractor is moving. I think the connector might be bad. Any way to bypass it? why, why, why??? :thumbdown:

It is an "afterfire" solenoid. Which cuts off the fuel when the engine is shut off, so when the engine is winding down after shutoff, it is not still cranking fuel into the engine, thus the muffler, after the ignition is cut off.