QuestionHi - I used my Craftsman mower for the 1st time this season, and I was able to cut the whole front lawn ok. I stopped the mower, moved to the back yard - but the mower refused to start any more. It was acting the same way as if you weren't holding down the "operator present" bar - not even catching at all. The engine is a Briggs & Stratton 12H802-2675-B1 with magnetron part# 802574...I checked the brake/kill switch assembly, and noticed that I was still measuring zero resistance between the kill switch wire and the engine chassis when the operator bar was held down. I then disassembled the top of the mower & removed the "Magnetron" magneto. When I metered between the kill switch wire that disappears into the resin around the secondary coil, and the plates of the armature - it reads as a dead short. I could not find a wiring diagram or schematic anywhere, so my question is this: Am I right in suspecting that the ignition is killed via the wire I mentioned, by the kill switch connecting it to the engine ground when the operator bar is released? If so I think I have a bad magneto as I think this wire when metered should show as isolated from the armature, which is bolted to the engine chassis when fitted to the engine. Thanks for taking the time to look at my question, I will look out for your reply.
AnswerHello Chris:
>>Sorry for the Delay. This Question was Located in the Question Pool and I can Only Answer Questions from the Question Pool when I am Not Answering Questions here or at the Other Site I Answer Questions at.
>>The Following is a Basic Instruction File I Made for Checking the Coil/Ign Coil/Magnetron/Armature on Small Engines. Any Input is Appreciated.
>>If the Unit Runs and Quits after 5 Minutes to 3/4 Hrs and will Restart after the Unit Cools (sometimes as little as 30min), then
>>Check for Spark as Soon as the Engine Quits.
>>Have a Good Plug with a Wire Around it Ready and when the Unit Quits Running, Remove the Plug Wire and Attach it to the Standby Plug. Check for Fire.
>> ***Be Careful, The Engine and Plug are Hot and I Suggest you Wear Gloves.***
>>If the Plug is Firing , then
>>Remove the Spark Plug from the Engine and USE IT to Check for Fire.
>>Sometimes a Spark Plug can have a Problem with Not Firing when Hot.
>>**To Check the Ign Coil if the Engine is Not Starting and Running at All; Remove the Spark Plug/s.
>>With a Good Plug, Wrap a Wire Around the Threads of the Plug and Attach the Other End of the Wire to the Engine Block.
>>Check for Fire at the Plug. If No Fire, then
>>Remove the Blower Housing (metal engine cover).
>>The Wire that is Connected to the Coil/Ign Module from the Shut Off Switch needs to be Removed (unplugged) from the Coil/Ign Module.
>>Now Check for Spark at the Plug.
>>If Spark, then the Shut Off Switch or the Wire is Bad.
>>If Still No Spark, then the Coil/Ign Module is Bad. If there are Safety Switches on this Unit and the Coil is Good; you Need to Check the Safety Switches for Being Bad and Check the Oil Guard Switch also.**
>>The Following is an Instruction File I Made to Replace the Ign Coil. **Using the Provided Site Addy, Locate the Breakdown for the Engine to Assist you in Doing this Repair if you Require it.**
>>Remove the Ign Module/Coil Lead from the Spark Plug.
>>Remove the Blower Housing (metal engine cover). Under this you will See the Ign Coil (has the Lead to the Plug Attached to it. Unbolt the Ign Coil and Remove the Coil.
>>Use a Section of a Soft Drink Carton (example: a Mt Dew 24 pk Side Panel Cut to 3" x 6".
>>Turn the Flywheel so the Magnet is Facing the Ign Coil and Place the Cardboard Section Between the Ign Coil and the Magnet.
>>Let the Magnet Pull the Ign Coil to the Flywheel and then Tighten the Ign Coil Mounting Bolts.
>>Turn the Flywheel and Pull the Cardboard Panel at the Same Time and Remove the Panel from between the Flywheel and the Ign Coil. Connect the Lead/s to the Ign Coil.
>>Replace the Blower Housing and Any Other Hardware you Removed to Remove the Blower Housing.
>>Attach the Plug Lead to the Spark Plug.
>>Now Start the Engine.
>>To View a Breakdown of this Unit Go to this Site Addy, http://www.searspartsdirect.com/partsdirect/index.action?sid=PSHx20080114x00001 and Enter the Model Numbers and Click Search. From this Page you can View Diagrams and Parts Lists.
>>If you Hit a Snag or this Does Not Correct the Problem, I Hope to be Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Be Safe and Happy. Thanks.
Good Luck
Respectfully
John
PS: I am Allowed to Answer 5 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Comments and Ratings are Greatly Appreciated. Thanks.
Respectfully
John
