Yamaha Diaphragm 738-14545-00-00. Overview. The Yamaha Diaphragm 738-14545-00-00 is a genuine original equipment manufacturer component designed to regulate pressure and fuel flow within your engine system. This essential part plays a key role in maintaining proper fuel delivery, supporting smooth engine operation and consistent performance.. Engineered to Yamaha's exact specifications, this diaphragm ensures a precise fit and reliable functionality. It is an ideal replacement for worn or damage