Over the past 80 years or so there have been innumerable carburetter designs by many different manufacturers, and it would be impossible for us to compile a detailed rebuild procedure for each one. However, all carburetters tend to follow the same principles of design, enabling us to give an indication of the various processes involved.
Carburetters are completely stripped.
Components are subjected to a four part chemical cleaning process which is the only effective way to remove dirt and corrosion from the internal circuitry as well as restoring the castings to their original appearance.
Castings are polished to a high standard, or stove enamelled. *
Mating faces are re-machined to ensure flatness.
The throttle spindle housing is re-bushed using P.T.F.E. lined glacier type bushes and line reamed to correct tolerance.
Steel components are de-rusted and inhibited.
Steel components are re-plated. *
Brass components are chemically brightened.
Brass components are polished. *
* Denotes concours service only.
Carburetters are now re-assembled using all new wearing components, i.e.:
Float needle valve
Throttle plate screws
Seals and washers
Any other components found to be faulty will be replaced. All internal components are adjusted and set as per manufacturer's specification.
Carburetters are then engine tested to ensure correct functioning of the following:-
Fuel level, Idle circuit, Choke mechanism, By-pass circuit, Pull down and fast-idle operation, Progression circuit, Correct throttle operation, Main circuit, Correct response to mixture adjustment, Pump circuit.
(Upon re-fitting to vehicle, normal adjustments will be necessary.)
Carburetters are given a final inspection and guaranteed for 12 months.