[Question] Jetting Size Input
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Jetting Size Input

  1. #1
    Member Rude Louie's Avatar
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    Default Jetting Size Input

    I'm running a somewhat mild BBC 468 with a set of Holley 660's. Currently the jets are 78 primary and 82 secondary. Last time out, checked a plug and it was pretty lean. Also noticed on top end it had a bit of "surge" is the best way to describe it. Anyways, from experience, is it recommended to run them square or staggered like they are? And what size do you guys run? Thanks

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    Senior Member Cheyenne321's Avatar
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    Just a thought. I would check for a vacuum leak around the manifold, may be an issue with the surging and lean plugs issue. Stray starter fluid around the gaskets while it is running and see if you notice any increase in RPM.

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    Where is your fuel press. at?

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    Member Rude Louie's Avatar
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    Quote Originally Posted by Cheyenne321 View Post
    Just a thought. I would check for a vacuum leak around the manifold, may be an issue with the surging and lean plugs issue. Stray starter fluid around the gaskets while it is running and see if you notice any increase in RPM.
    I'll give it a shot, thanks
    Quote Originally Posted by Gone Green View Post
    Where is your fuel press. at?
    7 1/2 to 8lbs

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    I ran a set (660s) 468 motor, for several years factory jet size, plugs were always black,ran good at wot.

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    Member Rude Louie's Avatar
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    I ran this same setup in my old boat without an issue. Maybe the "surge" that I'm feeling on top end is underwater hardware?
    Don't get me wrong the boat runs great! Just trying to do a fine tune

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    Quote Originally Posted by Rude Louie View Post
    I ran this same setup in my old boat without an issue. Maybe the "surge" that I'm feeling on top end is underwater hardware?
    Don't get me wrong the boat runs great! Just trying to do a fine tune
    There's nothing wrong with the hardware...I ran that set-up for years

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    I have a box of jets i can bring Sunday if you want you try some rejetting.

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    One thing he's not saying....it was 108" last time out..pretty much shitty no air

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    Senior Member Orange-Gasm's Avatar
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    Thats alot of pressure.
    I would'nt have to manage my anger if people could learn to manage thier stupidity

  13. #11
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    Cool

    We lowered the fuel press. from 9lbs. to 7.5 ran real good all day....timing and jetting was good

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