The 0.75mm pitch (allen head) replacement drain screw for the carburettor float bowl is shown right.

The 1.00mm pitch (cross head) replacement drain screw for the carburettor float bowl is shown left.

Please note that only a small number of later GPZ 900R A7-A8 models feature a 0.75mm pitch allen head drain screw (right) please double check which type is fitted to your machine. This type does not require an O ring.