Float Bowl Cover

For Amal
Monobloc Carburettors

The correct fuel level in the bowl of Amal's Monobloc series of carburettors (named as for the first time in Amal's product line the carburettor and bowl were cast together in a single 'block') is vital to a bike that runs well. The fuel level is controlled by a float that rises with the level of fuel to push on a needle that seats and blocks further ingress of fuel into the bowl. The fuel level can be adjusted by raising the seat relative to the bowl by adding washers beneath it, or adding shims onto the float so raising the needle relative to the seat. Later carburettors from Amal mounted the float on a tang that could be bent to allow adjustment.

Amal recommend checking on the fuel level by running some clear tube from the pilot jet to the bowl cover and seeing whether the level of fuel in the line matches the height of the pip on the cover. This method ineveitably results in spilt petrol and an uncertain diagnosis.

Laser cutting a cover in perspex with the pip marked on allowed rapid inspection of the fuel level in the bowl, and thus a quicker and less messy method to set the fuel level correctly.



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