Briggs electronic ign - no spark

[mr67gp]

I just got an older ('80s?) Sears LT/10 lawn tractor (freebie). It cranks, has compression, but no spark. I pulled the flywheel, and it has a big circular elecronic spark generator. I cleaned the rust off the ends of the magnets, the flying magnet on the fly wheel, and the arms of the coil. Still no spark. I pulled the ground wire completely off the throttle bracket to make sure it was isolated. Still nothing. This is the first e-ignition small engine I have played with.

So what am I missing?

Jim K in PA

[Archdean]

I just got an older ('80s?) Sears LT/10 lawn tractor (freebie). It cranks, has compression, but no spark. I pulled the flywheel, and it has a big circular elecronic spark generator. I cleaned the rust off the ends of the magnets, the flying magnet on the fly wheel, and the arms of the coil. Still no spark. I pulled the ground wire completely off the throttle bracket to make sure it was isolated. Still nothing. This is the first e-ignition small engine I have played with.

So what am I missing?

Jim K in PA

A new coil is what your missing IMO! They all had the same problem!!

[jbetts15]

have you tryed a new spark plug ??? some problems are as easy as replaceing the plug James

[mr67gp]

Plug was removed and cleaned, but it was fairly new and in good shape. Cranking the engine with the plug wire off the plug and held within 3mm of the head (ground) confirms that no spark is coming from the coil.

The mower ran fine when it was last parked, but that was almost a year ago. I have gone through the basics, I just dont know how to test the reluctor to verify that it is generating a field.

Dean, how do I test the coil, or is it just a plug & play part? There is no suspicious condition on the coil externally that would indicate a failure, but I suppose internal corrosion is possible, since the mower sat outside for the last couple of years.

Jim K

[Archdean]

Dean, how do I test the coil, or is it just a plug & play part? There is no suspicious condition on the coil externally that would indicate a failure, but I suppose internal corrosion is possible, since the mower sat outside for the last couple of years.

Jim K

This is what happnes to it, a small crack develops in side the coil , as far as testing it, you already have done that , it's either good or bad similar to the old style condensers on distributors ... Put on a new one and I'm sure you will be good to go!

[mr67gp]

Thanks Dean. I'll try and pick one up this week.

Jim K in PA

[mr67gp]

Ok, yours truly is an idiot. I never took off the dust cover under the flywheel to SEE THE IGNITION POINTS. Duuuuuh, as my kids would say. So the points look fine, so I still suspect that Dean is right and the coil is toast. Looks to be about $30 for a new one. I guess I'll bite the bullet and get one.

Jim K in PA

[dirtybernie]

jim. is the motor a briggs or tecumseh? i was given 3 old craftsmans with 10hp tecumsehs. if you have the tecumseh id be glad to help you out with a coil. bernie. :trink40:

[dirtybernie]

well DUHHHH! maybe i should have opened my eyes before typing the last post. sorry no briggs coils in stock at the moment but you never know what the weekend will bring :) :bonk:

[Ingersoll444]

Eaven though the points look good, they could still be bad. Wether dirt, oil, or the points becoming magntized, they may look fine, but not work. Wile you are there, I would eather replace them, or if I am not mastaken, there is a farly lowcost upgrade/update for the brigg's with points, to convert them to the new style solidstate system they use. May be something to look into, becouse I think it replaced the coil also.

[mr67gp]

Bernie,

No problem. It is a Briggs, and seems to be a very tight engine. I would do the electronic upgrade if I knew what was broken now. Once I get my JD finished I'll spend some time on this thing. I want to get it running for my son to go earn some money cutting lawns.

Jim K in PA

[dirtybernie]

jim. im going to let out one of my secrets. if you take a coil from a briggs powered push mower 3.5hp you will see the mounting holes are the same but the curve where it meets the flywheel is different. if you clamp twords the end with vise grips and grind the ends on a bench grinder it will work. while ive never done this to a customers mower ive done it on several of my own. in fact the one on my amf is going 4yrs strong! just take the ground wire and mount it on the throttle plate where the old 1 is. im prob going to catch some flack for this jury rig but oh well. bernie. :trink39: