O.S. Engines FT-300 Gemini - Manual (Page 7)

CARBURETTOR
The needle-valve and throttle lever locations are inter-
changeable by reversing the carburettor. This can be done
as follows:
Remove the carburettor carefully by unscrewing the two
screws which secure both carburettor and choke valve.
After reversing the carburettor, re-insert it into the intake
manifold, taking care not to damage the 0-ring in the
manifold.
Carburettor and choke-valve
fixing screws Fig. 2
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