Need help with Carb adjustment

Discussion in 'Technical' started by mike75mav, Jun 28, 2008.

  1. mike75mav

    mike75mav Member

    Joined:
    Mar 12, 2002
    Messages:
    758
    Likes Received:
    5
    Trophy Points:
    90
    Location:
    Bremerton, WA
    Vehicle:
    1975 maverick 4 door; 1971 Bronco frame off restoring
    I have a 70 Mav 250 engine. The carburetor is a carter RBS single barrle. I just got done rebuilting it and trying to set it up on the car. I cann't get it to idle the engine dies. It will run if you keep the gas on. There is no idle adjustment expect for fast idle and the mixture. From what I could see you would have to bend the linkage to adjust the idle.

    Has anybody else worked on this type of carb? I really need to get this done. Car has been down for 2 weeks.

    I don't want to rebuild it again.
     
  2. comet666

    comet666 RAISE HELL AND DRINK WINE

    Joined:
    Jun 27, 2007
    Messages:
    325
    Likes Received:
    1
    Trophy Points:
    92
    Location:
    Sweden/Gothenburg
    Vehicle:
    Comet -74 Inline Six 250, 4.1 AT
    There are three screws to mess around with, one for the fast idle, one for mixture and one for curb idle, from the passenger side you have got the mixture to the right and the curb idle to the left, on the other side (or the carb) is the fast idle (cam and adjuster)...

    Before you crank the engine, step on the gas to the floor, to get the choke (fast idle) in the right position, when you got the engine warmed up (10 minutes) you, depress the gas a little and you will go from fast idle to just idle...

    The fast idle screw is supposed to be on the first mark on the cam when in fast idle.

    I´ll keep on posting, but tell me if I´m only telling you stuff you alreday know..?:hmmm:

    Robert.
     
  3. comet666

    comet666 RAISE HELL AND DRINK WINE

    Joined:
    Jun 27, 2007
    Messages:
    325
    Likes Received:
    1
    Trophy Points:
    92
    Location:
    Sweden/Gothenburg
    Vehicle:
    Comet -74 Inline Six 250, 4.1 AT
    Make sure you got all the vacuum ports either plugged or hooked up where they are supposed to, and that everything on the carb moves freely without any sticking or binding..
     
  4. Andysutt

    Andysutt '72 Comet GT

    Joined:
    Dec 30, 2002
    Messages:
    3,086
    Likes Received:
    3
    Trophy Points:
    112
    Location:
    Conway Arkansas
    Vehicle:
    1972 Comet GT
    Well said on the vacume lines, impossible to adjust a carb if it has vacume leaks.

    As for holding it on the floor, hes referring to right at first, not to run it for 10 minutes w/ it on the floor
     
  5. comet666

    comet666 RAISE HELL AND DRINK WINE

    Joined:
    Jun 27, 2007
    Messages:
    325
    Likes Received:
    1
    Trophy Points:
    92
    Location:
    Sweden/Gothenburg
    Vehicle:
    Comet -74 Inline Six 250, 4.1 AT
    Sorry I´m such a bad writer, I thought for the first time I could really contribute with something, thank you for straightenig that 10 minutes thing out...
     
  6. Andysutt

    Andysutt '72 Comet GT

    Joined:
    Dec 30, 2002
    Messages:
    3,086
    Likes Received:
    3
    Trophy Points:
    112
    Location:
    Conway Arkansas
    Vehicle:
    1972 Comet GT
    No problem. Just didnt want him to misunderstand and blow it up. lol
     
  7. Dan Starnes

    Dan Starnes Original owner

    Joined:
    Mar 10, 2002
    Messages:
    5,235
    Likes Received:
    52
    Trophy Points:
    146
    Location:
    West Central IL
    Vehicle:
    Stallion, 72 Grabber, Sprint, 77 4dr Maverick
    I had this problem a couple years ago. My 77 had no idle screw, some of the later cars did not have idle screws. But, mine did have the threaded hole to put one in. The carb was junk and I used another carb. But I learned that at least the threaded hole is there. Just need to get a screw to put in it. If yours does not have a threaded hole for some reason, have you thought about drilling and tapping one in?
    Dan
     
  8. Andysutt

    Andysutt '72 Comet GT

    Joined:
    Dec 30, 2002
    Messages:
    3,086
    Likes Received:
    3
    Trophy Points:
    112
    Location:
    Conway Arkansas
    Vehicle:
    1972 Comet GT
    I've never heard of them not having one... I've seen the missing before, and it run like crap, but never not having one.

    Of course, you learn something new everyday. So, this may be the case.

    As for drillling and tapping it, I'd just go w/ a new carb
     
  9. mike75mav

    mike75mav Member

    Joined:
    Mar 12, 2002
    Messages:
    758
    Likes Received:
    5
    Trophy Points:
    90
    Location:
    Bremerton, WA
    Vehicle:
    1975 maverick 4 door; 1971 Bronco frame off restoring
    OK, I'll try to answer everyboby here. There is only 2 adjustment fast idle and the mixture both on the passenger side. The linkage is setup to where there is no place to put a screw for idle. This is a 70 carb the ones after would have a screw for idle.

    The vaccuam lines are good no leaks.
     
  10. Dan Starnes

    Dan Starnes Original owner

    Joined:
    Mar 10, 2002
    Messages:
    5,235
    Likes Received:
    52
    Trophy Points:
    146
    Location:
    West Central IL
    Vehicle:
    Stallion, 72 Grabber, Sprint, 77 4dr Maverick
    Andy is right, I lied.
    Dan
     
  11. Andysutt

    Andysutt '72 Comet GT

    Joined:
    Dec 30, 2002
    Messages:
    3,086
    Likes Received:
    3
    Trophy Points:
    112
    Location:
    Conway Arkansas
    Vehicle:
    1972 Comet GT

    You lied?

    I wouldn't think you'd sdo that. lol

    I just have never seen like that.
     
  12. comet666

    comet666 RAISE HELL AND DRINK WINE

    Joined:
    Jun 27, 2007
    Messages:
    325
    Likes Received:
    1
    Trophy Points:
    92
    Location:
    Sweden/Gothenburg
    Vehicle:
    Comet -74 Inline Six 250, 4.1 AT
    So are we talking about two or three now...? :dancing:
     

Share This Page