Ranger's not gonna like this, Yogi......

[rsnik 1]

We have had a lot of rain and I have been pushing the Speedy Green around like a madman to get some fertilizer soaked into the lawn. Between rains I went out to mow, couldn't decide whether to mow or bail one area. Was "mowing" a very tall, wet patch of lawn at WOT when the 7013 instantly lost spark. I put a spark checker on and, yep, no spark. She has near new points and condenser. Points are not burned or broken and are gapped properly. I have a horrible feeling I know what this is. The drive shaft to the bgb is connected to the flywheel on the back of the engine, right? A high load at WOT could cause the flywheel key to shear. The instant that happened your spark would be gone, right? Is there any test to verify this, short of pulling the engine? A man offered to buy my 3416S yesterday and I said yes. He bought a 3416S with a front end loader on it in NH. When he tried out the bucket the load caused his transmission/axle tube assembly to physically break into pieces and he wants mine for parts. If he shows up today that leaves me with 3 non running Simplicity tractors! This would be funny if it wasn't unfunny. Typical Simplicity guy, eh? (owns a shed full of tractors but the lawn's a foot tall.)

[Nick 0]

quote:

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Originally posted by rsnik
If he shows up today that leaves me with 3 non running Simplicity tractors! This would be funny if it wasn't unfunny. Typical Simplicity guy, eh? (owns a shed full of tractors but the lawn's a foot tall.)

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I feel for ya. It sounds like my troubles. Just waiting for our house reno to get done so I can start some restorations and put my tractors back in service. I ended up hiring a friend to cut the lawn for the time being. I need to dig my deck out of my neighbors barn to hook up to my landlord, but with the amount of the stuff that his Son jammed in there it may never see the light of day for a while.

[KSever 1]

quote:

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I have a horrible feeling I know what this is. The drive shaft to the bgb is connected to the flywheel on the back of the engine, right? A high load at WOT could cause the flywheel key to shear. The instant that happened your spark would be gone, right? Is there any test to verify this, short of pulling the engine?

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This is an easy repair, about 1 hour.

[rsnik 1]

Hi KSever, Boy do I like it when you talk dirty like that. Can you give me any more information? An hour is what it would take to load it on the trailer and drop it off at the Big Bux Fixit Shop. I hope that's not what you mean. Do you mean pull the engine and pull the flywheel? The tractor is well maintained and my last thought before it happened was "Man, have I ever got this tractor running good". Do you agree that's probably what happened? Thanks, rsnik

[wilm169 1]

I think I would check for a wire that might have fallen off.

[rsnik 1]

Super suggestion since I recently replaced the ignition switch and plug in connector, splicing the harness in with new butt connectors. I just went out in the dark with a flashlight and checked. Everything seems solid and no joy. I will go over it again in the morning. Good idea.

[MikeES 310]

If the flywheel key is sheared you should still have spark...but not necessarily at the right time or intensity. Unless you hit something (and stopped the engine abruptly) may cause a sheared key, but typically not a heavy load that did not instantly kill the engine. I would guess you have another problem.

[PatRarick 0]

quote:

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Originally posted by MikeES
If the flywheel key is sheared you should still have spark...but not necessarily at the right time or intensity.

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Mike, this is true only with a partially sheared key. The flywheel magnets pass by the coil just as the points open, and a spark is generated. With a completely sheared key, the magnets will not pass by the coil in time with the opening of the points and there will be no spark. Magnetron ignition is an exception. Since the "points replacement" is part of the coil, all that is required to generate spark is for the magnet to pass the coil. The flywheel can be spun 180 degrees out of time and the spark will be just as hot every time the magnet passes the coil.

[rsnik 1]

I understand how battery ignition works. I also understand the system on an outboard motor where a charge coil on a stator under the flywheel gets excited by a magnet spinning in the flywheel creating around 150+ volts of DVA (peak reading) AC current which gets converted to DC by a rectifier and stored in a capacitor until it gets triggered and shoots through a coil and hits the spark plug. I obviously don't understand the series of events with the magneto and points with Briggs ignition. I think UCD put up a link on how to troubleshoot your Briggs ignition at some point and I better go find that.

[rsnik 1]

Hi MikeES, I bought the 7013 from a car lot in very good condition with lots of obvious recent work (new carb, new starter/gen etc.) I think the car lot had gotten it from an estate sale. However the car lot guy had tried out the mower on some weeds out back and had hit something so hard it almost sheared off one of the 2 bolts holding the blade on the center spindle. When I redid the deck I was worried the spindle shaft might be bent. That hit may have partially sheared the key and mowing a heavy, wet area at WOT sheared it off. I searched the forum and read the Briggs ignition guide. I did not use a Briggs 19368 spark tester set at .166 but rather a CDI electronics model 511-9766 set at .166 inches and there is no spark at all. I rechecked the wiring I did recently on the ignition switch and it dawned on me (heck, if the ground wire dropped off the switch it would not cause a lack of spark, it would cause the engine to keep running when you turned the key off). I think it's the flywheel key but, Hey! KSever says that's a 1 hour job! I'll probably eat a Powerbar, throw an extra scoop in the coffee pot and be done in 15 minutes. Thanks PatRarick for saying the points open just as the magnet creates a field on the magneto, collapsing the field and sending the energy to ground via your spark plug wire where it fires the plug when jumping across the air gap of the plug. If it was possible to have spark occur with the points closed on a magneto system I was going to have to go back to school because I don't understand.

[rsnik 1]

I have to correct myself on something. If the ignition ground wire (kill wire) dropped off the ignition switch and the bare end of the wire fell into contact with a good ground it would ground out your ignition and you would have no spark. Trouble shooting step #1 for all outboard motors that use ignition kill wires and have no fire on any cylinder is "disconnect all kill wires AT THE PACK." In other words if the kill wire is shorted to ground anywhere along it's length it will still kill the spark.

[RedbarnRick 0]

Check the condenser slip in the old one and see if it runs, whenever mine get wet the spark ceases, I have a handful of them that went bad,finally replaced the gasket on the point cover and have been lucky for a while

[rsnik 1]

Hi Rick, Thanks! I'll give it a try. The points and condenser are relatively new and everything looked clean and dry. I am not an expert on condensers (although I slept in a Holiday Inn last night). I thought if the condenser went bad you would still have spark, but your points would pit and burn very quickly. Thinking about it though (hope I didn't strain anything) if the condenser is bad and creates a path to ground it would have the same effect as your points being closed all the time. If this works I will owe you for 2 much needed service manuals and saving me from pulling an engine. Would you prefer my first born or an overmortgaged house?

[Doll 0]

Not something you see every day but the cam can wear and the points stop closing. You can check this with a continuity tester or just set the point gap a little tighter and see if it fires. Also, The ground wire for the mag or the laminations can lose ground. If you have to pull the engine, I would clean those just to be safe. I have an engine that only runs with the points set at .036. Have never figured that one out. I asked here once but no one had any ideas. Anyway, Good luck.

[rsnik 1]

Fixed it. It was a combination of Rick and Doll's suggestions (thanks to both). Put in new condenser, got intermittent spark. Checked the spark in the dark with a spark checker so I could see any spark. Had the points cover off and I could see major points bounce, as in points sparking erratically like crazy. Went to set the points in daylight when I discovered that they would not stay set. The cap screw you turn to adjust the points had the threads stripped on the end so no matter what you set the points to they bounced every time the plunger hit them because the screw is pulling out of the threaded hole in the block.

[comet66 0]

Good for you, it's tough to trouble shoot something when you have more than one problem going on at the same time.

[rsnik 1]

Thanks John, Sadly not done yet. Put a new belt on, checked everything, was out mowing in the dark (headlights work good). She just hummed for about an hour and then that familiar points shorting out sputter started. Shut her down and will see what's up come daylight. Maybe I didn't tighten the nut enough on the points adjustment screw.

[Roy 0]

A Mega-Fire electronic ignition module will eliminate the points & condenser and solve the problem. Just a suggestion.

[rsnik 1]

Thanks Roy, I have been thinking about that all day. I borrowed the points off the 7016H to fix the 7013S. I have borrowed so many parts off the 7016 it's going to disappear entirely if I don't knock it off. Another set of points is, I think, $27. These points were nearly new but cheaply made; the set screw that stripped looked like pot metal. The points from the 7016 were old (I had to soak them in Evap-O-Rust)but very well made. A Mega-Fire is less money than pot metal points and the neighbors won't, once again, see the lawn half mowed and the tractor sitting way out in the middle of it (you know they think you got over bevaraged and fell off it, LOL)