Page 1 of 2 12 LastLast
Results 1 to 10 of 15

Thread: A little enlightenment please regarding "four stroking".

  1. #1
    TreeHouser flashover604's Avatar
    Join Date
    Sep 2014
    Location
    Lancaster Ohio
    Posts
    359

    Default A little enlightenment please regarding "four stroking".

    Hi all. After a lot of Internet sleuthing regarding new saws and tuning I've run across a term that I THINK I understand. FOUR stroking. I've been around four stroke and two stroke engines most of my life. When someone is talking about a chainsaw engine four stroking, this is what I THINK they mean. When the engine is WOT it has a smooth sound but when it's four stroking it gets a sort of "buzz" or miss sound? Am I on the right track? I know on my two stroke bikes if I'm heavy on the throttle and the in the power band it's a smooth sound and smooth power but as soon as I back of it the load drops it goes into the kinda "lopey" condition. Am I thinking of the right thing here?
    That which does not kill you...usually makes you wish it did.

  2. #2
    Woods walker Sponsor Burnham's Avatar
    Join Date
    Mar 2005
    Location
    Western Oregon
    Age
    63
    Posts
    14,631

    Default

    Sounds like you have the idea about right...I believe there are vids online with audio that demonstrate it, if you want to try to locate that resource.
    "Confidence is the feeling you sometimes have before you fully understand the situation."

  3. #3
    unsanitized BlackSmith's Avatar
    Join Date
    Mar 2005
    Location
    Upnya WV
    Posts
    3,314

    Default

    Madasons (sp) I think has a audio on their tuning page.
    Molon Pepe

  4. #4
    Woods walker Sponsor Burnham's Avatar
    Join Date
    Mar 2005
    Location
    Western Oregon
    Age
    63
    Posts
    14,631

    Default

    I'd call the four stroking sound a burble .

    Madsen's. http://www.madsens1.com/
    "Confidence is the feeling you sometimes have before you fully understand the situation."

  5. #5
    TreeHouser flashover604's Avatar
    Join Date
    Sep 2014
    Location
    Lancaster Ohio
    Posts
    359

    Default

    I found this video.

    http://youtu.be/6kZCSvIYylU

    When he lifts the saw you get the rough/burble sound I was talking about. I just wanted to make sure what I was hearing was what I was thinking!
    That which does not kill you...usually makes you wish it did.

  6. #6
    Woods walker Sponsor Burnham's Avatar
    Join Date
    Mar 2005
    Location
    Western Oregon
    Age
    63
    Posts
    14,631

    Default

    This is good for tuning info, and has a couple of sound clips, including the four stroking point.

    http://www.madsens1.com/saw_carb_tune.htm
    "Confidence is the feeling you sometimes have before you fully understand the situation."

  7. #7
    Woods walker Sponsor Burnham's Avatar
    Join Date
    Mar 2005
    Location
    Western Oregon
    Age
    63
    Posts
    14,631

    Default

    Quote Originally Posted by flashover604 View Post
    I found this video.

    http://youtu.be/6kZCSvIYylU

    When he lifts the saw you get the rough/burble sound I was talking about. I just wanted to make sure what I was hearing was what I was thinking!
    If you mean right at the beginning of the video, then no, that's not four stroking. Four stroking is observed at full rev without load. I'm not sure why that vid is titled the way it is. To my ear, it's not obvious at any point that the saw is four stroking. I could be wrong, my ears are not what they used to be .
    "Confidence is the feeling you sometimes have before you fully understand the situation."

  8. #8
    TreeHouser flashover604's Avatar
    Join Date
    Sep 2014
    Location
    Lancaster Ohio
    Posts
    359

    Default

    The wav. file on Madsen's site definitely helps. You can definitely hear it "clean up" towards the end of the file.
    That which does not kill you...usually makes you wish it did.

  9. #9
    Woods walker Sponsor Burnham's Avatar
    Join Date
    Mar 2005
    Location
    Western Oregon
    Age
    63
    Posts
    14,631

    Default

    "Confidence is the feeling you sometimes have before you fully understand the situation."

  10. #10
    Treehouser Cobleskill's Avatar
    Join Date
    Dec 2006
    Location
    Western New York near Lake Ontario
    Age
    60
    Posts
    3,275

    Default

    You have to be careful on the newer saws with a rev limiter. When they cut out on the rev limiter it can sound like four stroking. Don't know if they cover that in the vids. Checking your plug color tells you the story.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •