i have a glastron with volvo penta aq125 1982 i replaced the circulation pump and impeller for raw sea water ok when im putting it all back together,the black plastic neck with the cap,on heat exchanger the upper connection to the water pipes the gasket they give me is a small thin o ring and cant get a seal, i bought and ordered the part 2 times because it just cant be right . i tried it with another flat washer type gasket but it was to thick it seems like it would take a garden hose type washer can anyone give me some advise ? i dont know why i cant get the right part i even took the parts to the marine to purchase them
