1983 Yamaha 30EN Outboards Service Manual, Page 112Get this manual
8 Install the drive shaft, pinion washer, and pinion gearTorque the pinion nutTightening torque: 30 Nm (3.0kg, 25 ft lb)
The pinion washer lock tab should face toward the forward gear9Reinstall the gauging plug, and use feeler gauge to measure the distance between the plug and the pinion gear while pushing straight down on the 8mm bolt
LIST OF SHIMS When making shim adjustment, measure the clearance and according to the following graph, determine the thickness of shim to be added or removedAfter determining the pinion gear position, temporarily remove the pinion gear and drive shaftMeasuring the backlash of forward gear and reverse gear 1Place the forward gear in the gear case, insert the drive shaft from the water pump side, and mount the washer and pinion on the drive shaft, then tighten the nut