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D. Testing Petrol Supply between Tank and Autovac

  1. Is there any petrol in the tank?
  2. Yes. Close the throttle and turn the engine with the electric starter for a few moments. This should suck petrol from the tank into the autovac. Wait a moment a two for the petrol to flow, then open drain cock B. If the autovac is still empty, the fault lies either in

    (i) The suction system of the autovac, or

    (ii) The petrol supply pipe from the tank to the autovac.

    The former is the more likely alternative, and the probable seat of trouble is the autovac drop valve failing to close under the suction. Therefore, release clamp E; remove one of the pipes; pour petrol into autovac in order to flush the valve. If sufficient petrol is poured in it will also fill the carburettor float chamber and enable the engine to be started immediately. If the petrol supply fails again, stoppage in the petrol apply to the autovac is more likely to be the cause.

E. Clearing the Petrol Supply System between Tank and Autovac.

  1. Remove clamp E and lift out the pipe G which leads from the three-way tap F. Remove and clean with petrol the filter H, which is now accessible. When replacing, be sure it is in the position shown, with the point upwards.
  2. If the petrol supply fails again, empty the main petrol tank by removing drain plug I. Unscrew and wash in petrol the two filters J and K. Disconnect pipe unions Z at the tank and O and P at the three-way tap and make sure that the pipes are clear by blowing through them (the tyre pump can be used, with a rubber tube for connection).