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Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 12892
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
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The electronic magneto module on my 12.5 HP single cylinder

Customer Question

the electronic magneto module on my 12.5 HP single cylinder failed after about 6 years service . The local agent replaced it and it failed immediately , he said it must have been a faulty new one and replaced it with another . Used the mower (STIGA) twice and it failed again . Replaced the module again , started OK so put it on a trailer and took it home , drove it off the trailer and put it in the garage , next day tried to start it but no go . The technician then blamed the ignition switch , installed a new ignition switch and a new module . OK , used it 3 times , about 2 hours each time , drove it into the garage and a few days later tried to start it and again no go and no spark again .
I am an electrical engineer and I do understand the fundamentals of electronic magneto operation but I don't have a circuit diagram for the ignition module or for the STIGA mower .
This has cost a lot of money and I still do not have a satisfactory resolution , can you help.
Regards ,
Submitted: 1 year ago.
Category: Small Engine
Expert:  Briggs-Fan replied 1 year ago.

Hi Don , my name is ***** ***** welcome to Just Answer . You can take a digital multimeter and set it to DC voltage , unhook the ground from the coil and hook the red lead to it , then take the black lead and ground it . Turn the key switch back and forth from off to run , you should see no voltage at all , even if there is the tiniest bit of voltage then the ignition switch is back feeding power to the ground on the coil .

Another thing that can cause this is overheating . Did you change spark plugs before this problem started ?

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