2000-2005 Yamaha F40B Outboard Service Manual, Page 330Get this manual
SHIMMING (EXCEPT FOR USA AND CANADA)
(4) Calculate the pinion gear shim thickness (T3)Pinion gear shim thickness (T3)11.30 mmP100 mm
"P" is the deviation of the lower case dimension from standardIt is stamped on the trim tab mounting surface of the lower case in 0.01 mm unitsIf the "P" mark is missing or unreadable, assume "P" value of "0", and check the backlash when the unit is assembledIf the "P" mark is negative (-), then add the "P" value to the measurement
Example: If is "11.70 mm" and "P" T311.70 mm11.30 mm =0040 mm0.50 mm0.35 mm (0.014 in) If is "11.70 mm" and "P" T311.70 mm11.30 mm =0040 mm0.03 mm =0043 mm (0.017 in)