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Weird (to us) MS361 Issue...

Discussion in 'Chainsaw' started by HandLogger, Feb 27, 2019.

  1. HandLogger

    HandLogger ArboristSite Operative

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    We've been using a particular MS361 since roughly 2006 and, generally speaking, it's been our "go to" saw since we first purchased it (brand new). Apart from the common starting issues associated with his particular model, it is presently operating only intermittently.

    In fact, it runs fine one day, sits overnight and, viola, no fire ... and, when I write "no fire," I mean no visible spark. It seemed obvious to me that the ignition coil module is probably the prime suspect here, but then why does it sometimes run fine? One things for sure, it's an intermittent problem -- and that usually means a real pain in the arse. Any thoughts you might care to share on this intermittent issue would be happily received ... but, as a veteran who's seen his share of real problems, I'm not really interested in brand wars.

    And I almost forgot to ask ...

    As managed forest land owners, we operate saws very frequently, but I want to make one thing very clear: we are not Stihl mechanics. With this in mind, I wanted to also ask for thoughts on good basic testing tools that we can purchase to check our own saws with? Tools like a spark tester, a compression tester and a tachometer seem like a good idea for us, but I really have no clue who makes decent testing tools; hence, the question.

    Thanks very much for your time ~ Hand
     
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  2. HandLogger

    HandLogger ArboristSite Operative

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    Wow! Well, I guess the Stihl Ms 361 is just as awesome as I think it is. Apparently, I'm the only 361 owner who's ever had any trouble with one. :clap:
     
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  3. Welder56

    Welder56 Addicted to ArboristSite

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    Not sure why no one has posted on this.

    I’m not a seasoned veteran by any means but have some know how. Have you checked to see if there is the proper air gap between the coil and flywheel?
     
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  4. pioneerguy600

    pioneerguy600 Lost in Space Staff Member

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    I used to get into/answer to these problems but its just one of those areas where nothing is definite. Since the newer electronic modules are timed for fire by an embedded chip there is really no definitive test for reliability of the spark system. I now just replace the unit and so far this fixes the problem, not much to hash about or monkey with as the modules are not serviceable just R&R.
     
  5. MontanaResident

    MontanaResident Addicted to ArboristSite

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    In dealing with such issues, pulling all elect. connections and cleaning is a good place to start. Certainly remove any oils or grease, but look for any corrosion or heavy tarnish and etch it clean with a small metal brush or blade.
     
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  6. billyboy

    billyboy ArboristSite Lurker

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    Fluke and B&K are good Electronic testers, for voltage, resistance, continuity, Stihl has a tach for close to that $100, You can get a voltage light with a aligator clip on one end and a fine prick needle on the other but I don't know if it will stand up to the volts on the saw as it's for 12 v type automotive. You might check your s-plug wire that screws into the coil and shoot some cleaner on it or cut an 1/8 inch off it and you might do the same with your plug end with the spring. The old saws spring has an end leg bent at 90 degree, stuck thru the wire and then pushed in the boot. Could be a bad connect there. Most likely not but I'm not the smartest bulb in the box. If you do cut a bit off the end of the splug wire insert a needle or small nail in the center of the wire to help center the wire back on the coil screw.
     
  7. HarleyT

    HarleyT Tree Freak

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    The newer saws have coils that are more difficult to test for spark.

    How do you test for spark?
     
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  8. pioneerguy600

    pioneerguy600 Lost in Space Staff Member

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    The coil portion can test out good but still it will not spark , the timing chip essentially burns out/stops working so no more sparky.
     
  9. HarleyT

    HarleyT Tree Freak

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    Well, these newer models have a coil that is more finicky/difficult to test for spark, I have had a hell of a time selling coils in the past few years.
     
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  10. HarleyT

    HarleyT Tree Freak

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    Most of the time, the guys were testing by spinning the flywheel with a drill, or grounding the plug against something that wasn't grounded well, and the newer coils put out a pretty weak looking spark. So I am real gun shy when anyone declares that the coil has no spark, when in fact their problem may be just an old leaky carb needle.
     
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  11. HarleyT

    HarleyT Tree Freak

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    Sitting overnight, the saw may lightly flood, and the next morning, they try to start on choke, and things go from there.
     
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  12. HarleyT

    HarleyT Tree Freak

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    So I ask questions....

    Try to save everyone a lot of time, trouble and money....
     
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  13. HarleyT

    HarleyT Tree Freak

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    Since the saw is 13 years old, and the poster states that he is not a saw tech, the saw likely has seen a lot of use, etc...

    We need to step back and look at things, before we tell this guy to start buying new coils, or whatever. If it has never had any carb work, and no one has talked about compression, looked at the piston, etc.., we need to slow down and
    start with the basics.......
     
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  14. lone wolf

    lone wolf MS 200T King

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    I just tell my helper to touch the plug tip then if he dont yell its no good! OP check all the wires from the coil and see if any chafed also see what the boot contact looks like if it tight,did you try a new plug? Then get a new coil!
     
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  15. MontanaResident

    MontanaResident Addicted to ArboristSite

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    Like doing a muffler mod, or removing the limiter caps? I mean, do we even know if the saw is ported?
     
  16. HarleyT

    HarleyT Tree Freak

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    Or if they use synthetic oil!!!
     
  17. lone wolf

    lone wolf MS 200T King

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    OIC!
     
  18. HarleyT

    HarleyT Tree Freak

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    OINK!!!!
     
  19. HarleyT

    HarleyT Tree Freak

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    MOO!!!!
     
  20. lone wolf

    lone wolf MS 200T King

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    Nope! Oh I see! OIC! :baaa:
     

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