I have a 1991 Bayliner Ciera with small block v8 Mercruiser engine (with 950 hours) and Alpha One Gen II outdrive with freshwater cooling (heat exchanger). During a recent fishing trip in Puget Sound I ran the boat at normal operating temp @4300rpm for 20 minutes to the site, then shut off the engine after reducing to idle speed for about 2 seconds. After I shut the engine off I was unable to get the engine started again. The starter tried and tried but just a loud clunk with each turn of the key. After getting towed home, a new starter, and two weeks of time, I discovered the engine wouldn?t turn not because of a broken starter but water in my cylinders! Cylinder 2,4,6,8 to be exact. I?m guessing raw water backed up through the exhaust risers and fell down the manifold after my abrupt stop, or perhaps the riser or manifold has a hole in the raw water sleeve and is leaking into the exhaust section.
After discovering water in the cylinders, I removed all the spark plugs, turned the motor over at least 10 different times for about 10-15 seconds each time to purge the water from what seems like mostly cylinders 4 and 6 (all on the right side of the motor). I then tried starting the engine, but still the starter wouldn?t turn the flywheel. There seems to be an infinite amount of water in the cylinders, which led me to suspect that the problem lied in the a broken exhaust manifold or riser that had a raw water intrusion into the exhaust component thus leaking down into the cylinder top via exhaust valve and filling the cylinders with each turn of the starter. I then removed the source by unplugging the raw water hose from the bottom of the exhaust manifold and removed manifold and riser. Now when I turn over the engine less water comes out of the spark plug hole and exhaust value hole, but still a small dribble each time, at this point I can?t really tell if all the water is out or not, but I?m guessing not.
My boat is back in the fresh water lake and I?m fairly sure this water I?m seeing is fresh water (mixed with rust), not salt water from 2 weeks ago, NOT oil or antifreeze. My oil and antifreeze levels also haven?t changed. I did spray some anticorrosion spray into the cylinders that was recommended at the boat store to prevent further rusting.
At this point I have the exhaust manifold and riser and exhaust bellow disconnected on the right side of the motor, when I try to start the engine it putters and pops for about 10 seconds of starting with (lots of throttle!)but won?t catch.
Things I haven?t tried yet: pumping out any remaining water from cylinder with some sort of mini bilge tube pump. Then getting a new gasket for the manifold and riser then attempting to start the engine with them in place for proper exhaust back pressure.
My goal is to at least get the engine running for a few seconds before putting the manifold back on as I might need to disassemble more of the engine to troubleshoot this issue. But obviously I?ll put it back on if it might help. Also the riser and manifold are about 5-6 years old and probably should be replaced anyway.
I ran water through them with a garden hose on the dock and checked for leaks and the water stayed out of the center of the exhaust section and in the water sleeve only. Then again, I wasn?t under much pressure in my test.
Questions:
Has my engine corroded and is beyond repair from two weeks of salt water sitting in those cylinders?
Why doesn?t the engine start with one of the manifolds off now that most if not all the water is out?
If I put the manifold back on without the raw water cooling hose attached can I run the engine for 10-15 seconds to verify that the engine still even works?
Any advice would be awesome!
Thanks!!
After discovering water in the cylinders, I removed all the spark plugs, turned the motor over at least 10 different times for about 10-15 seconds each time to purge the water from what seems like mostly cylinders 4 and 6 (all on the right side of the motor). I then tried starting the engine, but still the starter wouldn?t turn the flywheel. There seems to be an infinite amount of water in the cylinders, which led me to suspect that the problem lied in the a broken exhaust manifold or riser that had a raw water intrusion into the exhaust component thus leaking down into the cylinder top via exhaust valve and filling the cylinders with each turn of the starter. I then removed the source by unplugging the raw water hose from the bottom of the exhaust manifold and removed manifold and riser. Now when I turn over the engine less water comes out of the spark plug hole and exhaust value hole, but still a small dribble each time, at this point I can?t really tell if all the water is out or not, but I?m guessing not.
My boat is back in the fresh water lake and I?m fairly sure this water I?m seeing is fresh water (mixed with rust), not salt water from 2 weeks ago, NOT oil or antifreeze. My oil and antifreeze levels also haven?t changed. I did spray some anticorrosion spray into the cylinders that was recommended at the boat store to prevent further rusting.
At this point I have the exhaust manifold and riser and exhaust bellow disconnected on the right side of the motor, when I try to start the engine it putters and pops for about 10 seconds of starting with (lots of throttle!)but won?t catch.
Things I haven?t tried yet: pumping out any remaining water from cylinder with some sort of mini bilge tube pump. Then getting a new gasket for the manifold and riser then attempting to start the engine with them in place for proper exhaust back pressure.
My goal is to at least get the engine running for a few seconds before putting the manifold back on as I might need to disassemble more of the engine to troubleshoot this issue. But obviously I?ll put it back on if it might help. Also the riser and manifold are about 5-6 years old and probably should be replaced anyway.
I ran water through them with a garden hose on the dock and checked for leaks and the water stayed out of the center of the exhaust section and in the water sleeve only. Then again, I wasn?t under much pressure in my test.
Questions:
Has my engine corroded and is beyond repair from two weeks of salt water sitting in those cylinders?
Why doesn?t the engine start with one of the manifolds off now that most if not all the water is out?
If I put the manifold back on without the raw water cooling hose attached can I run the engine for 10-15 seconds to verify that the engine still even works?
Any advice would be awesome!
Thanks!!
