Honda BF8, BF9.9 and BF10 Outboard Motors Shop Manual., Page 154Get this manual
10) Check the timing belt, replace the timing belt if it is worn or damagedCheck the timing belt and the related parts for oil and greaseIf contaminated with oil or grease, clean the parts and replace the timing belt with new one11) Install the timing belt on the timing belt drive pulley and then on the driven pulley taking care not to allow the alignment marks to come out of alignment12) After installation, be sure that the alignment marks are in the proper alignment13) Reinstall the removed parts:flywheel (P9-9)- pulse generator (P9-6)- charge coil (P9-71- starter case (P7-10)- recoil starter (P7-91- neutral start cable (P7-1)- left and right engine under covers (P5-2 and 3)- engine cover (P5-11 [21 TIMING BELT