Mercedes does not make a "marine" 616... (MTU "makes" all the MB marine engines, and none of them are under 700HP) other companies may convert this MB engine for use in a boat... but they would not change the IP. And if they did... why could you not use the drip method... which is why we are addressing the question...? Until there is more info or we have a more experienced opinion it's gonna be tough to help. I think the IP is not timed right... like it's skipped a tooth. Good logic however on the thought train...