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  1. #1
    CB750 Member 750slasher's Avatar
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    Question MAC 4 to 1 exhaust (Canister Style) with stock airbox questions

    I am looking at getting a MAC 4 to 1 exhaust (Canister style) for my CB750C street fighter style build.

    Just a few questions (I did a search but found nothing for my situation, if so, please attach a link for post).

    For the exhaust I want (Mac 4 to 1 canister style) with STOCK airbox, would rejetting be needed? If so, recommendations?

    OR would the engine just need "tweaked" in for the new exhaust?
    PLEASE CORRECT ME IF IM WRONG: If the new exhaust was installed but the airbox remained the same, there would be more flow on exit thus causing more air (on a small scale, due to the stock airbox, to be sucked in), this would cause more of a LEAN condition and I would adjust my fuel for more gas. AM I thinking right or way wrong?

    Anyone run a 4 to 1 MAC exhaust with stock airbox? Any help would be awesome.

  2. #2
    CB750 Member 750slasher's Avatar
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    So no one has input?

  3. #3
    Moderator dirtdigger's Avatar
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    Probably wont make a difference as long as the stock air box is used. Most problems with the CV carbs come from people changing jetting along with ditching the stock air box.

  4. #4
    CB750 Member 750slasher's Avatar
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    Quote Originally Posted by dirtdigger View Post
    Probably wont make a difference as long as the stock air box is used. Most problems with the CV carbs come from people changing jetting along with ditching the stock air box.
    Thanks for the input!

  5. #5
    CB750 Member 750slasher's Avatar
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    Anybody else have any opinions on this question? Just want multiple peoples take on this

  6. #6
    CB750 Enthusiast SeattleRod's Avatar
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    I just changed my original 4 into 4 exhaust on my -80 750 custom with a Delkevic 4 into 1 exhaust with stock airbox.
    After the swap, I did a vacuum sync and there was minimal adjustment needed.
    The bike runs and sounds great.



    Sent from my iPad using Tapatalk

  7. #7
    CB750 Member 750slasher's Avatar
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    Quote Originally Posted by SeattleRod View Post
    I just changed my original 4 into 4 exhaust on my -80 750 custom with a Delkevic 4 into 1 exhaust with stock airbox.
    After the swap, I did a vacuum sync and there was minimal adjustment needed.
    The bike runs and sounds great.



    Sent from my iPad using Tapatalk

    Great info! Thanks!

  8. #8
    CB750 Member 750slasher's Avatar
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    ***Update***
    Installed the MAC 4 to 1 canister style exhaust. Install was perfect, fitment perfect, quality top notch and the bike rides smooth.....no issues to report!

  9. #9
    CB750 Addict Wez_'s Avatar
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    Glad to hear the progress. Got a video of the sound?

  10. #10
    CB750 Enthusiast Skelee's Avatar
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    Mine has 4 to 1 and stock air box. Runs fine.

    Sent from my SM-A520W using Tapatalk

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