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My craftsman lawn tractor (917.273640 18.5 HP)won't start. I tested the battery with a volt meter and it is fine (12.5V), solenoid appears fine (12.5V across terminals) and when I bypass the solenoid and hook jumper cables from battery to starter, the starter turns the engine like normal but it wont kick over. I tested for a spark and do not see one with the tester. Almost one year ago the tractor would not start and a repairman replaced the ignition switch and armature magneto for a cost of just over $250.00. Is there a way to test these parts myself? If so, please send information this way. Any other suggestions on what to might be wrong also appreciated. Thanks
 

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My dad had a Chraftsman Garden tractor, when he passed we had the chore of getting it started. Turned over, had fuel, all safeties on, would'nt start.
The computer geek brother-in-law messed with it,took it apart,failed to put it back togeather and left me holding the bag. I wanna say there is this fuse in a white plastic tube, don't know where it goes but I changed it and it ran til the geek got on and it broke again. I changed the spark plug and ran fine. I then kept the key with me and only let my 9 year old boy cut grass and myself. My carpenter buddy has a good saying, fuel, spark and air. Get the piston thoes 3 things and thats it. Good luck!!
 

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Did you have the ignition switch in the on position when you were cranking it and checking for spark?When you bypass the solenoid it'll crank without the switch on but it won't have spark unless the switch is turned on.It could still be a safety switch acting up,you wouldn't know that unless you eliminate them one at a time and see if they are working.
 

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My dad had a Chraftsman Garden tractor, when he passed we had the chore of getting it started. Turned over, had fuel, all safeties on, would'nt start.
The computer geek brother-in-law messed with it,took it apart,failed to put it back togeather and left me holding the bag. I wanna say there is this fuse in a white plastic tube, don't know where it goes but I changed it and it ran til the geek got on and it broke again. I changed the spark plug and ran fine. I then kept the key with me and only let my 9 year old boy cut grass and myself. My carpenter buddy has a good saying, fuel, spark and air. Get the piston thoes 3 things and thats it. Good luck!!
You almost had the triagle there :fing02:

It's fuel, spark and timing. :cool:
 

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Discussion Starter #5
Did you have the ignition switch in the on position when you were cranking it and checking for spark?When you bypass the solenoid it'll crank without the switch on but it won't have spark unless the switch is turned on.It could still be a safety switch acting up,you wouldn't know that unless you eliminate them one at a time and see if they are working.
Thanks for reply. Lack of spark on the tester was when trying to start the mower with the key like normal and not bypassing the solenoid. Folks are suggesting to test the safety switches which I will do. The engine cranks like it normally does when starting but just won't kick over and run. I did maintenance in the spring and changed filters and spark plug. Fuel is fresh. I stopped the mower for a couple of minutes three days ago and it hasn't started since.
 

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Did you have the ignition switch in the on position when you were cranking it and checking for spark?When you bypass the solenoid it'll crank without the switch on but it won't have spark unless the switch is turned on.It could still be a safety switch acting up,you wouldn't know that unless you eliminate them one at a time and see if they are working.
I just tried starting the it again by jumping the starter with the key in the on position and no luck, spark tester was also negative for a spark when jumping the starter with the key in the on position.
 

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My craftsman lawn tractor (917.273640 18.5 HP)won't start. I tested the battery with a volt meter and it is fine (12.5V), solenoid appears fine (12.5V across terminals) and when I bypass the solenoid and hook jumper cables from battery to starter, the starter turns the engine like normal but it wont kick over. I tested for a spark and do not see one with the tester. Almost one year ago the tractor would not start and a repairman replaced the ignition switch and armature magneto for a cost of just over $250.00. Is there a way to test these parts myself? If so, please send information this way. Any other suggestions on what to might be wrong also appreciated. Thanks
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For testing purposes only, locate and disconnect the magneto kill wire at the engine. I don't know where it is on your engine but possibly someone with a tractor similar to yours will give us a better clue. Usually the wire comes from underneath the engine shroud and is a single wire.

Be careful as this disconnection voids all safety features including killing the engine with the ignition switch. You can leave the switch in the off position for this test. If the engine starts and runs we can, for the moment, assume a safety switch(s) is the culprit. If it fails to start and run we've pinned down that the problem may be either a bad magneto or the kill wire that was disconnected could have a bare spot worn into the insulation possibly where it goes under the engine shroud.
 

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Discussion Starter #8
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For testing purposes only, locate and disconnect the magneto kill wire at the engine. I don't know where it is on your engine but possibly someone with a tractor similar to yours will give us a better clue. Usually the wire comes from underneath the engine shroud and is a single wire.

Be careful as this disconnection voids all safety features including killing the engine with the ignition switch. You can leave the switch in the off position for this test. If the engine starts and runs we can, for the moment, assume a safety switch(s) is the culprit. If it fails to start and run we've pinned down that the problem may be either a bad magneto or the kill wire that was disconnected could have a bare spot worn into the insulation possibly where it goes under the engine shroud.
I did remove the housing on top off the engine to look at the magneto and check the connections. The wire from the starter to magneto looks good and the connection is good. The spark plug wire from magneto and connection also looks good. These are the only two wires attached to the magneto. I thought about bypassing the solenoid and starter and jumping the magneto directly but the wire to it from the starter just clips into a plastic housing so I can't hook up the jumper cables to it. Is there a way to test the magneto?
 

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I did remove the housing on top off the engine to look at the magneto and check the connections. The wire from the starter to magneto looks good and the connection is good. The spark plug wire from magneto and connection also looks good. These are the only two wires attached to the magneto. I thought about bypassing the solenoid and starter and jumping the magneto directly but the wire to it from the starter just clips into a plastic housing so I can't hook up the jumper cables to it. Is there a way to test the magneto?
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Is there a way to test the magneto?[/QUOTE]
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Disconnecting the Mag kill wire is a test albeit somewhat shade tree style and due to my testing equipment, or lack of, and knowledge that's how I would have to do it.

I'm not familiar with an engine that has a wire from the starter to magneto. I'm sorry I can't be of more help. Maybe someone will be along that knows about that type of set up.
 

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Ok,that tractor looks like it has a B&S engine on it,correct?On the back side of your magneto,there should be a plug,pull it off,that's the wire that Maybar is talking about,with that wire off,and actually you don't even need to put the blower housing back on,crank the engine and check for spark,just make sure you keep your hands away from the flywheel.If you have spark now,it's something in the tractor,if not your magneto is bad.I don't believe that any of your wires are running from the starter to the magneto on that engine,the mag on that engine produces it's own power to create a spark.
 

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Discussion Starter #11
Yes 18.5 hp B&S engine.You are correct, black wire runs under the starter, looked like it was coming off it at first glance but does not come off it, it runs into a harness with other wires. I'll disconnect the wire to the magneto and see if I get a spark with the tester - No spark replace magneto, spark and something else is bad, possibly safety switch as others suggested. Thanks
 

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Replaced the magneto for approximately $35.00 and the tractor started on the first try. Thanks for all the help!! The one that was not working went in on July 29th of last year and looked to be rebuilt.
 

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I love it when a plan comes together. Another win for the MTF crew.

:MTF_wel2:

Now, szuchone, hop on over to the Introductions forum and give us a proper intro, and then stick around to see what kind of fun you can have with these nuts!

Steve
 
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