My Merc is making a bad tapping sound under the valve cover. Probably a tappet going bad? I need to know the setting for the tappets on this engine. The serial number is: 4460527.<br />Does anyone know offhand? Or know of a good link for the specs on this engine?<br />Also... does anyone know of a good lead subsitute? This engine was supposed to run on leaded gas and I figure the use of non-leaded might have led to the tappet noise.<br />Thanks.....
