ignition problem

Old 06-01-03, 03:24 PM
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ignition problem

I am working on a briggs & stratton model #143302 Type #502551 horizontal shaft engine. I have no spark I tried a new plug still no spark. Set the air gap on the flywheel still nothing. I removed the coil to clean it up and noticed a wire attached to the coil that runs into the engine. What is this wire for? I have never seen a engine with a external coil ignition with a wire like this. It has me stumped. Thanks for the help and info in advance!!!!
Old 06-01-03, 04:52 PM
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The wire you see connected to the side is the kill wire. If you have an ignition switch, then it is connected from the coil to the switch and when you turn the switch off, it connects that wire straight to ground, thus stoping the spark and killing the engine. If you don't have an ignition switch, then when you slow the throttle down all the way, or release the bar that is connected to a safety switch, it contacts the kill wire sending it to ground and killing the engine. Check to make sure that this kill wire doesn't have a bare spot on the insulation, if it does then this would keep the engine from starting. A simple test is to disconnect it from the coil and try starting the engine. Keep in mind that since the kill wire is disconnected, you won't be able to stop the engine. To stop it you will either have to reconnect the kill wire, or pull the choke, or put your hand over the intake. To be able to test the engine as discribed will require the shroud to be removed. Keep in mind that the shroud directs the air over the cooling fins to cool the engine, keeping it from overheating and freezing up, so don't run the engine for more than 2 or 3 minutes without the shroud. If it starts, then that kill wire has a short in it. If you still don't have spark, then it is the coil. A coil costs about $20 to $25. Hope this helps!!!!
Old 06-01-03, 05:51 PM
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Thanks for the reply I will try what you described to me and see if that works. It is an older engine that I got from my uncle and it probably has not been started in about 10 years. The thing that has me stumped also is that the plate with the model and serial number gives the specs for a point gap. Thats what had me stumped on what that wire was for I thought it also had points.
Old 06-02-03, 01:47 AM
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Yes...you probably have points unless the coil has been swapped over to electronic ignition. The wire on the coil will go under the flywheel if it has points. The test mower17 gave you is correct for testing an electronic ignition system, but not for the ol' points system. If it has points, you might consider buying a replacement coil that has the electronic ignition module built in and do away with the points. This is the simple and reliable way of doing it. If you want to keep the points, you will need to remove the flywheel and relace the points and condenser to tune it up and you may find your problem there.

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