308 GTBi How do I richen the fuel mixture? | FerrariChat

308 GTBi How do I richen the fuel mixture?

Discussion in 'Technical Q&A' started by reflex, Nov 15, 2003.

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  1. reflex

    reflex Karting

    Nov 11, 2003
    Brighton U.K
    I have just got a 1980 308 gtbi. It came with a very nice stainless sports exhaust system. However the previous owner must have just bought for asthetic looks. Upon changing the air filter for a high flow K&N deal it appeared as if no attention has been paid to the induction system. The factory fitted air filter was dirty and is obviously designed to severely restrict the airflow. On fitting the K&N there was an immediate, and quite noticeable, increase in response from the engine.

    I'd like to try and richen the mix a little using an exhaust prope, but I don't know where the adjustment screw is. I'm guessing this might improve things a little further still.

    Any ideas?


  2. mondial86

    mondial86 Formula Junior

    Nov 1, 2003
    Full Name:
    David Holmes
    There is a 3 or 4 mm allen screw just in front of the air induction (black boot) on the fuel distributor and you turn it . Verry small amounts ,this is really an idle mizture adj. but it does efect the whole range
  3. 308GTS

    308GTS Formula 3

    Dec 27, 2001
    Would you turn it clockwise to lean it out like a carb or clockwise to richen?
  4. Doc

    Doc Formula Junior

    Sep 13, 2001
    Latham, New York
    Full Name:
    Bill Van Dyne
    Clockwise=richer ( at least on a QV). However, be very careful in fooling with this. Even a 1/8th of a turn can change things.
  5. reflex

    reflex Karting

    Nov 11, 2003
    Brighton U.K
    Hence, I intend to use an air/fuel meter to measure the mix.
  6. Dale

    Dale F1 Veteran

    Oct 7, 2003
    Full Name:
    Dale Juan
    3mm,as doc said very small ajustments on k-jet make a big change in fueling.

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