MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Weber DGAV

I have a 73 B with a weber 32/36 DGAV installed with manual choke. The car has the aftermarket "square" fuel pump producing 3 lbs. of pressure at the carb's fuel inlet. I've carefully rebuilt the weber and very carefully set the float level. However, when I turned on the switch, the fuel in the bowl flowed over into the carb throats and dripped down the manifold. I have reset the floats to about 1/2 of the recommended level, but the bowl still "weeps" gas into the throats, and will flood the engine if it's not started right away. Can someone tell me why this thing overflows? Why won't the floats stop the excess fuel?
Les Delinski

Les. Check the operation of the needle valves. My daughter's 77B also has the square box fuel pump and a Weber DGV and does not have a problem such as you describe. You made in incorrect decision when you reset the float height. The Weber DGV series is designed to operate at 3-3.5 psi with the float set to the factory recommendation. My first thought would be a needle valve that was not sealing correctly. When you reset the float level and the problem was still there, that tends to confirm the bad needle valve diagnosis. A secondary possiblity would be a leaking float which does not have sufficient lift to shut off the needle valve. This would also not be affected by resetting the height of the float because the float itself would not be functioning properly. So, check the needle valve, and while you are at it, inspect the float and see if it sloshes when rattled near the ear. Les
Les Bengtson

Les D, I agree with Les Bengston. Check the needle tip and brass seat in particular for any obstrustion. Also check that the float assembly is free in its vertical movement and that the needle retainment clip is in the proper position. Reset to fac. settings and it should run properly.
victor gardino

This thread was discussed on 21/02/2004

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.