I'm back.

Discussion in 'General Discussion' started by OldSkool, Sep 13, 2019.

  1. OldSkool

    OldSkool Active Member

    May 8, 2010
    Boating on Raystown Lake, Pa
    restored 1976 SRV200
    188 Mercruiser I/O
    I'm trying to get Old Skool back in the water after a brief hiatus. Ordered up a new 2 bl carb and installed however I can't get it to idle down past 900rpm. Idle adjust screw is backed all the way off the linkage. Any ideas? Linkage may be incorrect? The part number was a direct cross from the original. Also trying to install an HEI distributor however there is no vacuum on the old one. Where should I pick up the vacuum? Carb or intake manifold?
  2. Espos4

    Espos4 Well-Known Member

    Jan 1, 2017
    Long Island NY
    2007 240 Sundeck
    350 MAG Bravo 3 W/DTS
    Disconnect your linkage and see if the idle comes down. It may be binding and not allowing the throttle to close completely.

    Also look for open vacuum ports on the carb and intake manifold. Any vacuum leak will increase idle speed. The carb to manifold gasket could a source of a leak too.

    Distributors typically like ported vacuum, not manifold vacuum.
    Look for a vacuum port that is above the throttle plates, not below.
  3. Thornton69

    Thornton69 Active Member

    Sep 15, 2014
    Northern BC
    1981 245 SDC
    2020 Solar 420
    '97 5.7 Bravo 2
    '20 Merc 25 EFI Jet
    Confirm the throttle plates are seating together with the idle screw backed out. A faulty seal at the base gasket could also cause an issue.

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