1991 Yamaha Outboard Factory Service Manual 9.9 and 15 HP, Page 127Get this manual
9.9N Carbu retor: Stamped mark Choke bore Venturi bore Main bore Main nozzle Main nozzle bleed Main jet Main air jet Pilot outlet Pilot jet Pilot air jet Bypass Bypass Bypass Pilot screw (turns out) Throttle valve angle Valve seat size Float level (gauge): Idling speed Trolling speed Reed valve: Thickness Valve lift Bending limit (M.J (MAJ (P.O (P.J (PAJ (B.P1) (B.P.2) (B.P.3) (P.S (Th.v) (V.S 138 14 13 1.2 Dia mm (0.047 Dia in 0.5 mm (0.078 0.02 in 850950 rmin 670770 rmin 0.2 mm (0.008 in) 1.3 mm (0.05 in) 0.2 mm (0.008 in)
6E770 32 mm (1.26 in 15 mm (0.59 in 21 mm (0.83 in 3.1 Dia mm (0.122 Dia in)16 mm (0.63 in) ABl1.2 Dia mm (0.047 Dia in #104 0.8 Dia mm (0.031 Dia in 1.3 Dia mm (0.051 Dia in #52 0.8 Dia mm (0.031 Dia in 0.9 Dia mm (0.035 Dia in 0.9 Dia mm (0.035 Dia in