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Stihl BR 400 problems..need help

Discussion in 'Mechanic and Repair' started by tennstripeking, Nov 10, 2009.

  1. arska75

    arska75 LawnSite Member
    from .
    Posts: 3

    Hi, could someone measure the resistance of primary coil, between those thin wires?
    Ohter goes to kill switch and other to body.
    secondary coil is about 7.4K ohm from spark plug wire to body.
  2. rotti1968

    rotti1968 LawnSite Member
    Posts: 169

    Stihl does not offer any form of resistance testing for the coils. Based mostly on the fact that they are not true coils but modules and have internal chips and circuit boards, you will never get a good reading. Stihl's testing consists of spark or no spark, weak spark or loss of spark when hot, and kill circuit testing. If you isolate the coil and the kill circuit tests good, and your boot and connector are good, then your problem is with your coil and you just replace it.
  3. arska75

    arska75 LawnSite Member
    from .
    Posts: 3

    okay, first the spark was weak when coil warmed, idle was good. now from coil cames only 30 volts ac. Maybe coil is End of life ;(
    I have removed the kil circuit.
  4. tennstripeking

    tennstripeking LawnSite Member
    Posts: 19

    Hey guys just wanted to give yall an update on my br400. I replaced the ignition module and it is working like a champ. I also changed fuel filter, and spark plug. Thanks to all of you for the helping me solve the problem.
  5. arska75

    arska75 LawnSite Member
    from .
    Posts: 3

    I'm looking used or oem module because in finland original price is about 100$

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