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5105 rev limiting?

Discussion in 'Chainsaw' started by 2stroked2smoke, Nov 17, 2010.

  1. 2stroked2smoke

    2stroked2smoke ArboristSite Operative

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    Hey guys, just purchased a new dolmar 5105. Ran a few tanks through it and decided to turn it up to 14000. I leaned it out and can't get it to read right on my tach. It revs up to 1300 forjust a sec, then jumps back down to 10500 and holds. Is this a rev limiting coil? No matter how much I adjust the carb it does the same thing. I finally had to adjust it in the wood. Thanks
     
  2. Andyshine77

    Andyshine77 Addicted to ArboristSite

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    Yes it's the rev limiting coil that giving you bad tac readings. To get a good reading tune the saw dog rich than slowly lean it put until you get to 14,300 or so, the limiter shouldn't kick in until 14,500. This will give you a safe rpm and the saw will still run well.
     
  3. 2stroked2smoke

    2stroked2smoke ArboristSite Operative

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    So your saying I might have been too lean to begin with and was beyond the rev limiter already. That could be. I'll have to try it again tommorrow. Thanks
     
  4. Andyshine77

    Andyshine77 Addicted to ArboristSite

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    Correct, and it's caused many inexperienced users to burn their saws up. For cutting firewood you want to set the saw somewhere under the limiter, for your saw 14,200-14,300 is safe.
     
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  5. tdi-rick

    tdi-rick Addicted to ArboristSite

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    I remember one of the Dolly dealers (Scott, Steve or Kyle) mentioning that at some time in the 5105's life that Dolkita were dropping the 14,500RPM coil and going back to a 13,500RPM limit coil, maybe that's already happened ?
     
  6. Edge & Engine

    Edge & Engine Addicted to ArboristSite

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    PS-460, PS-510, PS-5105 coils limited at 13,800 as of March 2010.
     
  7. gemniii

    gemniii Addicted to ArboristSite

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    Are the rev limiters for some govt rule or CYA for the mfg?
     
  8. 2stroked2smoke

    2stroked2smoke ArboristSite Operative

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    If this is true, then you can't set the high side with a tach? I ran the saw for the first few tanks at the dealers settings.After having trouble setting with my tach, I put it in the wood and set it so it would fourstroke when lightly put in the wood and clean out and two stroke when putting it full into the cut. Is this the only way to set the saws with the rev limiter coils?
     
  9. Edge & Engine

    Edge & Engine Addicted to ArboristSite

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    No you can still use a tachometer.
     
  10. SawTroll

    SawTroll Information Collector

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    Thanks for the info! :)
     
  11. 2stroked2smoke

    2stroked2smoke ArboristSite Operative

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    How can you set a saw to run at 14300 with a tach, if the coil limits out at 13800
     
  12. SawTroll

    SawTroll Information Collector

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    No-go, unless you change the coil out! :help:
     
  13. RTK

    RTK ArboristSite Operative

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    Something is wrong. I just purchased a 5105 built in july of this year, along with that I bought my first tach just for the heck of it. I usually tune by ear but wanted to see how the rpms related.
    First thing I did was buy a used 5100 muffler and mod it, then I removed the needle limiters and twist the high out some. Made a few cuts with it (way rich) and then set the rpm to 13400 by leaning. Haven't run it since but the next time I do I will see where the coil limiter is set at. I was hoping to set it at 14200 next outing but it looks like they have changed the coil, gonna find out the next time I run her
     
    Last edited: Nov 18, 2010
  14. Edge & Engine

    Edge & Engine Addicted to ArboristSite

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    You can't run it at 14,300 rpms. It's limited to 13,800. I would set it about 13,500.
     
  15. blsnelling

    blsnelling Site Sponsor

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    Why so rich? Is the factory spec exaggerated?
     
  16. Edge & Engine

    Edge & Engine Addicted to ArboristSite

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    No, I just don't like running them up against the limiter. It's probably not real important, but I don't see much gain in 200 rpms.
     
  17. blsnelling

    blsnelling Site Sponsor

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    I thought spec was actually 14,300-14,500 or something along those lines. I realize the limiter is below that, simply meaning you have to tune it in the wood. 13,500 would be a good starting place to do that. 800-1000 RPMs is a lot of power left on the table if richer than needed.
     
  18. tdi-rick

    tdi-rick Addicted to ArboristSite

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    Brad, read the thread ;)
     
  19. blsnelling

    blsnelling Site Sponsor

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    I have. I just find it odd that you would want to tune it to 13,500 and leave it, reguardless of what the limiter is set to.
     
  20. SawTroll

    SawTroll Information Collector

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    Changing the rpm limit below what is optimal without doing other changes makes no sense to me, but I have a hunch about why they did it. Hopefully, they made other changes as well....
     

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