Genuine Yamaha Fuel/Water Separating w/Aluminum Head 1/4"  -  Highly recommended for 2/4 stroke outboards.  Consult your service manual before purchasing.

10-Micron Fuel/Water Separating Filter
They are a primary line of defense against ethonol-related fuel system issues. Highly recommended for all two stroke and four stroke EFI outboards and two stroke HPDIs. Also excellent for carbureted engines. New, improved 10-micron filter provides superior filtration ahead of the engine's onboard filters and injectors. Large filtering and water capture areas maximize filtration while maintaining adequate flow rate for larger engines.