After three engines and lots of work, what I thought was fixed is back. I have twin 4.3 FWC mercruisers and have had hydrolocking problems with them ever since I bought the boat. At first I thought the fluid problem was missing shutters and a dieseling engine. I replaced the missing shutters and reconditioned the heads. The problem remained so I installed three inch spacers on both engines due to the boat's low waterline with four adults on board. After having one engine go bad, I decided to replace both with brand new base engines. After one of these engines lost oil pressure resulting in a spun bearing, Upon inspection, the engine showed signs of water intrusion. Lost my warranty and put one of the old engines back in. Right now, the boat has one new engine,(110hrs) the other is one of the old engines with new rings, head gaskets and recon heads on it. Both engines smell of antifreeze when running and the heat exchangers are consistantly low when checked before a trip. Put the boat in for the season last night and when I tried to start the older of the two engines, it was locked up. After inpection, the liquid in the cylinders is coolant. When I left the ramp, both heat exchangers were full. Now, both are low. The newer, port side engine started fine but has the tell tale coolant smell. The only parts that are common to all of the engines in this boat are the exhaust manifolds. I let the engine sit for twenty or thirty minutes with the plugs removed and shot a healthy one out both sides of this morning's hydrolocked engine. I drained the manifolds and waited again. Turned the engine over and no more water in the cylinders. Anybody else think that this boat may have frozen resulting in four cracked manifolds? I don't believe it to be a head gasket problem on any of the engines. Thoughts and suggestions would help clear my thoughts. I would like to repair this boat once and for all before I make my own personal reef site! I was a mechanic for 13 years so gimme all the tech you can muster, I'll understand
I don't have the serial numbers but they are 1994 carberated models. The fluid is in both sides of both engines. Alpha 1 gen II drives with new water pump impellers. WOT is 4200 RPM's I think, usually run at about 2900 though.
Forgot to mention, the starboard engine is the original engine from the port side. The port engine, the one that runs but has the coolant odor and steam while running is a base engine from marine engines in holliston mass. Not happy with it but it runs.
Forgot to post the problem. I had the raw water going to the risers instead of the spacers. I think that may have allowed enough heat to degrade the new gaskets causing them to leak into the exhaust on boht sides of the engine. New Quicksilver gaskets and happy boating. Thanks