carb sucks?

[bond]

TR7....backfires on tickover when warmed up.  The first carb appears to be working as it should, on tickover its sucking air, if i cover the air intake on it the engine struggles and stops.  The second carb does not suck air on tickover and when i cover the air intake on it nothing happens.  Both carb suck air when reved.  Any ideas, thanks in advance for any help    Dave

[Beans]

Sounds like one carburettor closes completely, so check position of the throttle discs to start with.
After that balancing the carburettors is the next step.
Also check the small plastic “stop” on the bottom of the piston is still in place.

edit ... I pressume the car has SU's fitted?

[JonathanW]

There are several cheap ballance tools available, and I don't think the expensive ones are much better that the budget types (Gunsten). Your biggest challange is the linkage. You get it perfect, then as you tighten the clamps it goes off again, start your day on decaff!!