Yamaha 25BMH 30HMH Factory Service Manual, Page 268Get this manual
LOWR LOWER CASE 6-18 DISASSEMBLING THE LOWER CASE 6-18 CHECKING THE DRIVE SHAFT SLEEVE 6-19 CHECKING THE NEEDLE BEARING 6-20 ASSEMBLING THE LOWER CASE 6-20 SHIMMING 6-21 SELECTING THE PINION SHIMS 6-22 SELECTING THE FORWARD GEAR SHIMS 6-24 SELECTING THE REVERSE GEAR SHIMS 6-26 BACKLASH 6-28 MEASURING THE FORWARD GEAR BACKLASH .6-28 MEASURING THE REVERSE GEAR BACKLASH .6-29