I have sourced maintenance parts like filters and zincs from Toadmarine.com: https://shop.toadmarinesupply.com/marine_diesel_direct/Yanmar/index.php?p=include&contentsection=yanmar&contentname=engine&engine=SB12
I replaced the “Mixing Elbow” and sourced the new one from: http://shop.toadmarinesupply.com/ships_store/?p=shopsearch&q=124770-13500&x=-559&y=-113
I have replaced the starter and sourced the new one from here: http://www.ebay.com/itm/NEW-STARTER-MOTOR-YANMAR-MARINE-ENGINE-YSM-YSM12-YSM8-/151022240793?pt=Boat_Parts_Accessories_Gear&vxp=mtr&hash=item2329a08419
I have replaced the fuel lift pump and sourced the new one from here: http://crowleys.com/fuel-pump-1gm-1gm10-2qm20-y-105582-52010