In loving memory of Kenis D. Keathley 6/4/81 - 3/27/22 Loving father, husband, brother, friend and firewood hoarder Rest in peace, Dexterday

Muffler Modification?

Discussion in 'Chainsaws and Power Equipment' started by Chvymn99, Nov 10, 2013.

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  1. clemsonfor

    clemsonfor

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    When I say that mod. On those saws done that way its hard to hear the 4 stroke. Combo of a small saw and restricted muffler.
     
    clemsonfor, Dec 29, 2013
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  2. MasterMech

    MasterMech The Mechanical Moderator

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    Very lean. I would crank the H out (Counter-clockwise) an 1/8th of a turn and start there. even that might be too lean but you will be a lot closer.



    Listen at 3:30, you'll hear me crank it leaner, the saw will clean up and "scream" and then I turn it back to rich again. You can hear the saw change tone as it transitions from 4-stroking to 2-strokeing and back repeatedly. Don't be afraid to set it pig-rich, turn the H out until it runs like crap and then back in until it starts to get better. Then find where it starts screaming and back off until it 4-strokes (blubbers) nicely.
     
    MasterMech, Dec 29, 2013
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  3. DexterDay

    DexterDay Administrator

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    X3.. To lean. Needs fattened up. MM's video is a good one to go by.
     
    DexterDay, Dec 29, 2013
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  4. Chvymn99

    Chvymn99 Moderator

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    Alright, I warmed it up and ended up turning it almost 3/4 out. 1/2 was were it just started and 1 was very noticeable. To my inexperienced ear anyways. But went back to original position to hear the difference and back to the 3/4 position. It wasn't quite noticeable till you went from one end to the other. Then rereading the last comments. Thank you guys.
     
    Chvymn99, Dec 29, 2013
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  5. Pyroholic

    Pyroholic

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    Definitely lean. Do you have, or have access to a tach? Don't be afraid to go too rich. That's what I did at first until I got more comfortable tuning. Plugs are cheaper than a top end.
     
    Pyroholic, Dec 29, 2013
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  6. Pyroholic

    Pyroholic

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    My 290 came in at about 1 turn out after mm. A little more when very cold out.
     
    Pyroholic, Dec 29, 2013
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  7. clemsonfor

    clemsonfor

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    And when u get a big saw u can easily hear it. I have a 390 with exact mod. Its hard to hear!! Come listen to the 650 u can hear a 4 stroke!
     
    clemsonfor, Dec 29, 2013
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  8. Chvymn99

    Chvymn99 Moderator

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    Yes, I got one from my SS for Christmas. Thats my plan. I just wanted to learn by ear, now I'd like to see how it tachs out. Just like ins MM video.
     
    Chvymn99, Dec 29, 2013
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  9. Chvymn99

    Chvymn99 Moderator

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    So now that you guys have gotten me to this point after the muffler modifications.

    Now that I've got a Tach, Id like to use it to see where it is. Where do I find the tach numbers for this saw? All that I could find was Idle RPM of 2800. That way I can mimic MM video and try to learn more. Thank you guys!!!!!:thumbs:
     
    Chvymn99, Dec 29, 2013
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  10. clemsonfor

    clemsonfor

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    clemsonfor, Dec 29, 2013
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  11. MasterMech

    MasterMech The Mechanical Moderator

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    Idle rpm is all that you should really try to set to. The other numbers are for a stock saw, which you no longer have. I use them as a guide and nothing more.

    Once the dual-port muffler went on the 460 in that vid, tuning to the stock 13,500 rpm set it pig rich. Was much happier up at about 13,800 IIRC.
     
    MasterMech, Dec 29, 2013
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  12. Chvymn99

    Chvymn99 Moderator

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    Well, took it outside this morning to cut some mulberry. It did a great job, no bog downs kept chewing as it was going through. This really has made a big difference in the performance....:thumbs:... No its not the 362 or the 034, but its back in my saw lineup. Probably will go in the back of my truck for scrounges now. May be if I get time this afternoon I'll play with the tach while its snowing. Thank you guys now that I've got this on my face:D.....
     
    Chvymn99, Jan 1, 2014
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  13. Chvymn99

    Chvymn99 Moderator

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    I was relooking over this posting. I guess I didn't post a picture of what my muffler mod ended up looking like.

    [​IMG]
     
    Chvymn99, Jan 7, 2014
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  14. clemsonfor

    clemsonfor

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    I did mine just like yours, but I think I'm going back into mine and drilling a half inch hole in that center area. Get more area open and that's a straight shot out except for deflector. Should be louder get a bit more power and sound better.
     
    clemsonfor, Jan 7, 2014
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