1991 Yamaha Outboard Factory Service Manual 9.9 and 15 HP, Page 35Get this manual

Fuel flow aFuel flow in the fuel pump
Fuel 2Check valve (suction) 3Diaphragm (outer) 4Check valve (delivery) 5Needle valve

1Diaphragm (inner)

• ATV
• Jet Ski
• Outboard Motors
• Personal Watercraft
• Snowmobiles
• Stern Drives