1991 Yamaha Outboard Factory Service Manual 9.9 and 15 HP, Page 43Get this manual
cChecking the pilot screw Check the pilot screw for wear and replace it as required Good condition
Unsuitable
1Pumpcover
2Diaphragm (outer)
3Gasket (outer)
4Fuel pump body 6Gasket (inner)
5Diaphragm (inner)