Re: Water in all cylinders on Merc 5.0 (305)
Actually a leaking exhaust manifold to exhause elbow gasket will put enough water in to a cylinder to shut down the moter. Those moters have overlapping valve systems, the exhaust valve closes after TDC, so it does suck back a little into the cylider. Usually it's cylinders 5-8 that get the water, especially 7 and 8. <br /><br />The exhaust elbow gasket has been an extremely weak point in all mercruiser motors, that is why they have finally gone to dry stack manifolds and elbows, just like the race motors. <br /><br />I think that more than likely it's either a bad gasket, or more likely if you've never had the elbows off, the sealing surfaces between the exhaust elbow and manifold are shot. I see this sort of thing all the time, it happens worse in salt water boats, but is a problem for all mercuisers. <br />Have it checked out, but it may have already done it's damage.<br /><br />Scott<br />I actually pull my elbows every other year, clean the surfaces on both manifold and elbow, inspect for wear and replace with new gaskets. The gaskets are cheap, and the whole process takes about 2 hours. Plus I've peace of mind that I'm not going to injest water, and tuilp a valve, or bend a conrod, or bend a valve. All of which happen during a hydrolock.