Page 1 of 2 12 LastLast
Results 1 to 10 of 12

Thread: ZS carb on 1980 Spitfire

  1. #1
    Senior Member
    Join Date
    Nov 2010
    Location
    Rutland, VT
    Posts
    57
    Chats
    0

    ZS carb on 1980 Spitfire

    Hi,
    Ok now that winter is over in the Northeast, I am getting the car on the road. I bought this in Oct 2010 and have been getting to know it through the winter.

    I have noticed an issue with carb. I did take it apart clean and new gaskets. It does have a funky manual choke that doesn't work and looks like a replacement/homemade job. The issue I have is that the piston gets stuck all the time. Prior to starting I remove the air filter and can not budge the piston with my finger. I have to take a screwdriver and pop it up to get it to move freely.

    Is it possible to be out of round somehow? What to do?

    BTW, the Home CFO has given approval to purchase a new carb if needed. I was contemplating a Weber DGV.

  2. #2

    Re: ZS carb on 1980 Spitfire

    Any pictures of the parts in question?

  3. #3
    Jedi Trainee SkinnedKnuckles's Avatar
    Join Date
    Jan 2005
    Location
    Cordova, TN
    Posts
    387
    Chats
    0

    Re: ZS carb on 1980 Spitfire

    The carb top cover may not be oriented correctly which could bind the air valve. There are a couple of alignment "bars" on the top & bottom part. I think the writing on the cover is oriented across the car as if to be read from the cockpit.

    Also, the top cover needs to be tightened in a sequence and not just cranked down around.
    Brent

    '73 TR6

    The harder it is to reach the drop light the more likely it is to shine in your eyes.


  4. #4
    Senior Member
    Join Date
    Nov 2010
    Location
    Rutland, VT
    Posts
    57
    Chats
    0

    Re: ZS carb on 1980 Spitfire

    ok, here are pics.
    Photobucket Triumph Carb

  5. #5
    Senior Member
    Join Date
    Nov 2010
    Location
    Rutland, VT
    Posts
    57
    Chats
    0

    Re: ZS carb on 1980 Spitfire

    Oh BTW I did tighten in a sequence. I did it small tighten adjustments at a time, moving in a star pattern.

  6. #6
    Jedi Trainee SkinnedKnuckles's Avatar
    Join Date
    Jan 2005
    Location
    Cordova, TN
    Posts
    387
    Chats
    0

    Re: ZS carb on 1980 Spitfire

    Well, a try, anyway. I don't see how the choke spring could be causing the problem, though, as the AV kinda floats on the mixing chamber pressure. You're not running real lean and having the air valve drive the needle into the jet on deceleration? Just guessing...
    Brent

    '73 TR6

    The harder it is to reach the drop light the more likely it is to shine in your eyes.


  7. #7
    Yoda poolboy's Avatar
    Join Date
    Oct 2007
    Location
    S.W. Mississippi
    Posts
    3,060
    Chats
    0

    Re: ZS carb on 1980 Spitfire

    Unscrew the damper piston (white knob) and remove it from the damper well, then see if the air valve still sticks.
    Also from looking at the pictures, the carb and the manifold's mounting flange doesn't seem to be a match; not that it would make your air valve stick,..nevertheless..
    DRIVE 'EM IF YOU GOT 'EM

  8. #8
    Senior Member
    Join Date
    Nov 2010
    Location
    Rutland, VT
    Posts
    57
    Chats
    0

    Re: ZS carb on 1980 Spitfire

    poolboy,

    thanks I will try that and report back. I thought that was a mis-match on the carb and manifold flange. I wonder if this had a different carb that was removed.

    skiined - no, the problem is that after the car sits for awhile, like overnight, I can not move the air valve with my finger. I have to lever it free with a screwdriver, then it will move freely.

    Could it be a carb that was put together from several and clearances are not in tolerance?

  9. #9
    Yoda poolboy's Avatar
    Join Date
    Oct 2007
    Location
    S.W. Mississippi
    Posts
    3,060
    Chats
    0

    Re: ZS carb on 1980 Spitfire

    The shaft with the damper piston may be tilted in the well, putting a bind on the air valve, But as soon as you remove the damper piston as I sugested, you'll know.

    OR, might be a bit of corrosion that needs cleaning. About the only way to tell is disassembly and test fitting components until you uncover the culprit.
    DRIVE 'EM IF YOU GOT 'EM

  10. #10
    Yoda swift6's Avatar
    Join Date
    Jul 2005
    Location
    Fort Collins, Colorado USA
    Posts
    4,126
    Chats
    0

    Re: ZS carb on 1980 Spitfire

    ZS carbs are much more forgiving of tolerances than SU's, especially when it comes to the air piston as it uses the rubber diaphragm and not a close tolerance fit between the airvalve and the bell. If the damper piston is ok, you might also check the height of the jet and or how far out (down) the needle is. The widest part of the needle near its base, could be sticking in the jet.
    Shawn
    TR8FHC-Melted


Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •