when I use the engine on my 28' '80 O'Day there is a distinct exhaust odor which lingers in the main salon and in the hanging locker. I suspect that there is a leak somewhere in the exhaust system. The engine is a 15 horse Zephyr Saildrive. It was manufactured by OMC and is a two-cycle engine. Is there any one place in particular I should be looking? The manual which came with the boat indicates that it is Vetter system. Changing to a diesel while desireable carries an $8,000 price tag. If anyone knows where I can get a less expensive diesel I am interested.