British-Cars.org

Welcome to the DMR Site for British 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 - SU Carburetor Throttle Shaft vacuum leak - Tip

SU Carburetor Throttle Shaft vacuum leak - Tip

If you throttle shafts develop a vacuum leak due to wear, the following may be a stopgap solution. In order for this to work, the shafts must not be excessivly worn that they wobble and they must protrude at least 1/8 inch beyond the carburetor. Find an “O” ring with an ID that is slightly less than the diameter of the shaft and with a 1/8 inch cross sectional diameter. First apply a thin coat of silicone grease to the shaft ends. Then use an epoxy adhesive (JB Weld is a good choice) and carefully apply glue to the carburetor body ensuring that no adhesive is applied to the shaft. Slide the “O” ring onto the shaft and apply more adhesive to the “O” ring where it meets the carburetor to ensure a good seal.

You can check for vacuum leaks by spraying a flammable solvent such as carburetor cleaner at all possible leak locations while the engine is running at idle speed. If the engine RPM changes you have a leak at that location.

Frank Grimaldi
Frank Grimaldi

Frank, what a clever idea, congratulations. I wish my 'little grey cells' worked like yours. Mike
J.M. Doust

This thread was discussed on 29/09/2011

MG MGB Technical index

This thread is from the archives. Join this live forum now