Your HD10 is 2 cylinder, 2.5 HP. It will need new leather primer seals with instructions to replace them if you want it to start and run at low speed. Send $10.00 cash and a SASE (self addressed Stamped envelope) to Lloyd Lautner, 9289 North Long Lake Road, Traverse City Michigan 49685. More good info at; pochefamily.org/outboard Sorry that the price has increased, but getting hard to find the proper oil tanned leather to make new seals.