Yamaha 25BMH 30HMH Factory Service Manual, Page 322Get this manual
SHIMMING
E Example: If M2 is "78.79 mm" and "R" is "+5", then: T280 mm(+5)100 mm78.79 mm80 mm0.05 mm78.79 mm1.26 mm (0.050 in) If M2 is "78.75 mm" and "R" is "-3", then: T280 mm(-3)100 mm78.75 mm80 mm0.03 mm78.75 mm1.22 mm (0.048 in) (3) Select the reverse gear shim(s) (T2)Calculated numeral at 1100th place more than 1.00 1.10 1.20 1.30 or less 1.10 1.20 1.30 1.32 1.0 1.1 1.2 1.3