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MS261 VS MS261 C-M Comparison

Discussion in 'Chainsaw' started by Mastermind, Sep 1, 2013.

  1. El Moobs

    El Moobs Are we there yet?

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    Your 261s really are fast Brad. I got to play with one at a GTG awhile back. It was very impressive. I think it was faster that the ones I do.
     
  2. Tigdim

    Tigdim Got him...

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    Well I finally got time to finish up the Muffler mod for mine... Hoping to give it a test run tomorrow night. I left the stock port alone, and the side port is currently .171 in^2. I have plenty of room to go bigger if needed. But Should be about 75% of the mufflers intake with both exhaust ports. I do have screens on both so like I said I may need to go bigger if I don't notice an improvement.

    Fitment of the screen needs to be refined, Installed the deflector with Jackbolts and the gap is thicker than the screen... I also should have shortened up the over all length of the deflector. The edge of the hole for the bottom jackbolt cut into the radius so I have a small gap down there.

    I might just make a spacer to sandwich the screen to the body for now until I figure out if I should go bigger then try again with a slightly different deflector design.

    261C Muffler mod 1st attempt.jpg


    Aaron
     
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  3. Tigdim

    Tigdim Got him...

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    WOW, I would have never guessed how much of a difference the muffler mod makes on the 261C.

    Its not that I was really skeptical of the muffler mod helping out... Its just I was not sure how noticeable it would be.

    I used to race RX-7s put on the the "Racing Beat" exhaust that claimed like 20% gains at the time... (now its up to 32%, It also requires a fuel cut defender because it allows the turbo to spool so much better from 7-8 psi to 10-11 if I remember correctly) At that time, that exhaust wowed me at the difference it made.

    This muffler mod was even better. I went out to the city dump today over lunch and cut up large chunks of miscellaneous wood.... before with moderate-heavy pressure I could bog the saw down in oak with the 18" bar fully buried and a freshly sharpened chain. Now with the 20" bar... it did not skip a beat just changed pitch and kept cutting! That is until I REALLY leaned on it!!!

    I liked the saw before... I really did not think it would make this big of a difference! Now I really want to send it Randy and have him work his magic... but that's not going to happen. My wife says I already have too many expensive hobbies... :( Its not like I have that many... :rolleyes:

    Just going to make time to adjust the squish, once the snow is too deep to cut on the farm. My wife is going to start referring to me as Tim Taylor again...

    [​IMG]


    Aaron
     
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  4. sweetchuck

    sweetchuck New Member

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  5. sweetchuck

    sweetchuck New Member

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    ok Im new to this site and the way it works but I believe ive got it figured out how to post now. May have posted blank replies sorry.My question is I have a brand new ms261 cm and looking at these muffler mods and cant quite tell if you put a hole and deflector on one side of the muffler do you also remove and bore out the screen inseret and screw. Do you do both or just one?
     
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  6. MustangMike

    MustangMike Addicted to ArboristSite

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    Welcome to the site. Randy (Mastermind) ports saws, and ported saws need a much larger exhaust opening.

    On a stock saw, a smaller hole would be more appropriate. The M-Tronic system will adjust for it (but may give you a few fits while doing it).

    If you pull the cover and remove the screen the factory hole will function much better. Then, If you drill a hole on the opposite side, you will need to add a deflector to keep it from warming your hand.

    I would just add a 1/4" hole to the cover on the same side, close to the seam (as far away from the front as possible). Look before you drill to make sure it will vent clear of any obstructions. Make sure you remove all filings before you re install it. (You will not need a deflector for this mod).

    That is the first step to waking the saw up a bit, good luck & enjoy.
     
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  7. DexterDay

    DexterDay Addicted to ArboristSite

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    Ported or Not, I like to open them up a lot. I've thrown the % to exhaust port rule out. I have a MS 250 I got for next to nothing and it's a little screamer now that it's been opened up and retuned!
     
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  8. blsnelling

    blsnelling Site Contributor

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    Me too!!!
     
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  9. MustangMike

    MustangMike Addicted to ArboristSite

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    Some saws like it, some don't.
     
  10. DexterDay

    DexterDay Addicted to ArboristSite

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    After some of the muff mods I've seen at GTG's (including one without the front cover)!! I'm with the go big or go home bunch!!
     

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