Rebuilt Rochester 2B Carburetor - Now Idle Runs Very High

Discussion in 'Chevy Truck Forum' started by Lennie Friedman, Dec 10, 2017.

  1. MikeG

    MikeG Full Member

    Joined:
    Feb 26, 2011
    Messages:
    2,979
    Likes Received:
    2,228
    Trophy Points:
    113
    Occupation:
    Wind Turbine Technician
    Location:
    Richland, WA GMTruckClub.com

    @Lennie Friedman Easiest way to check the base gasket it to spray a little Carb Cleaner around the base while the truck is running to see if the idle/ RPM's change. If it does increase, you found your leak.
     
    Lennie Friedman likes this.
  2. JTWard

    JTWard Full Member

    Joined:
    Sep 3, 2012
    Messages:
    1,281
    Likes Received:
    969
    Trophy Points:
    113
    Gender:
    Male
    Occupation:
    I'm retired.
    Location:
    I live very close to the Delaware border with S.E.
    Been years, but those old chokes linkages often got rusty or fouled with dirt and oil residue ?.
     
  3. Lennie Friedman

    Lennie Friedman Full Member

    Joined:
    Jan 7, 2017
    Messages:
    41
    Likes Received:
    4
    Trophy Points:
    8
    Gender:
    Male
    Occupation:
    General Manager for a High Tech Manufacturing Firm
    Location:
    North Carolina
    Thanks fellas. I rebuilt the carb and certainly could have done something unitntentioanl to the choke.

    However it if is hot, and the throttle valve is wide open, would that choke cam still be affecting it?
     
  4. JTWard

    JTWard Full Member

    Joined:
    Sep 3, 2012
    Messages:
    1,281
    Likes Received:
    969
    Trophy Points:
    113
    Gender:
    Male
    Occupation:
    I'm retired.
    Location:
    I live very close to the Delaware border with S.E.
    Only if the choke , or it's linkage is holding it in a closed or partially closed position. To me I would think that would be a long shot. For example, if you hit the throttle pedal a couple of times as the engine was warmed up, then the choke SHOULD kick the choke open. This is something you would feel though Lennie.
     
  5. scavanger

    scavanger Full Member

    Joined:
    May 15, 2007
    Messages:
    1,791
    Likes Received:
    1,354
    Trophy Points:
    113
    Occupation:
    machinest working on retireing come June 2015
    does it only stall before it warms up ? when you say "throttle damper" do you mean the choke butterfly? If the choke is not set properly you can get to lean a mixture till the engine warms up. Cold engine requires richer mixture. check your linkage closely
    You may have the idle cam on incorrectly or some linkage on wrong causing the choke to not operate the way it should. This could cause it to be on the high idle at all times and it could cause stumble when cold due to the choke not being closed far enough. You may have to find a picture or another carb. to compare to.The choke/idle linkage can be confusing.
     
  6. Lennie Friedman

    Lennie Friedman Full Member

    Joined:
    Jan 7, 2017
    Messages:
    41
    Likes Received:
    4
    Trophy Points:
    8
    Gender:
    Male
    Occupation:
    General Manager for a High Tech Manufacturing Firm
    Location:
    North Carolina
    Got it. Thanks. It is possible I could have the linkage on incorrectly. I will take some photos to review.

    Appreciate your thoughts.
     
  7. leolkfrm

    leolkfrm Full Member

    Joined:
    Mar 2, 2008
    Messages:
    12,814
    Likes Received:
    7,969
    Trophy Points:
    113
    Location:
    N.Y.
    sorry been plowing snow and running to the hospital,

    yes, look at the actual cam for choke, make sure the base idle screw is not resting on the first step of cam, it will raise the idle about 200 rpm
     
  8. Lennie Friedman

    Lennie Friedman Full Member

    Joined:
    Jan 7, 2017
    Messages:
    41
    Likes Received:
    4
    Trophy Points:
    8
    Gender:
    Male
    Occupation:
    General Manager for a High Tech Manufacturing Firm
    Location:
    North Carolina
    Awesome and Thanks.! To confirm, base idle is the high idle, or idle for the choke? Sorry to be a pain, but do you have a pic of what it should look like?
     
  9. scavanger

    scavanger Full Member

    Joined:
    May 15, 2007
    Messages:
    1,791
    Likes Received:
    1,354
    Trophy Points:
    113
    Occupation:
    machinest working on retireing come June 2015
  10. leolkfrm

    leolkfrm Full Member

    Joined:
    Mar 2, 2008
    Messages:
    12,814
    Likes Received:
    7,969
    Trophy Points:
    113
    Location:
    N.Y.
    base idle is hot running idle, what you are trying to achieve
     

Share This Page