MG Car Repair: carb adjustment

Question
I have a stock 1976 MGB with rebuilt carb that when shut off and try to restart to soon floods out. If let cool off starts

Answer
Hi Doug

My first thought is that this is a hot restart problem due to a faulty heat shield between the carb and the exhaust manifold.  If your heat shield is damaged or missing, fit a new one.

The Zenith Stromberg carb has an automatic choke.  This can fail, causing a rich mixture when the engine is hot.  Not only will this give problems on restart, it will also use more fuel as you drive along.  If you are using more gas than usual, I would suspect the auto choke.

Old Stromberg carbs can also suffer from over-fuelling when the diaphragm starts to get old and hard (before it eventually splits).  A new diaphragm will be more soft and pliable, allowing the piston to rise further and let more air into the engine.

Finally, it could be a failing ignition coil.  Next time it happens, open the hood and touch the coil.  Is it hot?  If so, try fitting a new coil.