Yamaha Outboards 3P Service Manual, Page 44Get this manual
G640000
REED VALVE Inspection 1) Visually inspect for warping of the reed valveIf warped, measure the distortion with feeler gauges
Maximum reed warp: 1.5 mm (0.06 in) If the amount of warping is greater than specification, replace the reed valve2) Using vernier caliper, measure the valve stopper heightValve stopper height: 3.8-4.2 mm (0.15-0.17 in) If the valve stopper height is outside the specification, adjust it by bending3) Visually inspect for cracks on the reed valveIf cracks are found, replace the reed valve
G645000