Boat motor cylinders filling with water.

[walb0244]

I don't think it's such a great idea to be running the engine while out of the water. A crack or blown gasket = lots of smoke. You said you start your boat before you put it in the water, what's cooling the engine during that time?

When I say I start it before putting it in the water I'm talking about as the back of the trailer hits the water we start the motor. So the motor is running for 2 seconds out of the water. I was just trying that because everyone said water was going up the exhaust. Since I had the motor running when it went in the water and left it running till out of the water. Then I knew the water didn't go up the exhaust. That was the only reason I did it that once.

If your oil is not milky and you don't see water leaking from your block or manifolds then no crack
Sounds like a riser gasket or a interior perf of your exhaust cooling jacket since your engine is running fine
Try draining your exhaust. Jackets just when you shut it off and see if that eliminates the cylinder water
.02

The oil in the motor looks fine. It doesn't look milky at all. What is the exhaust jackets? The last time I pulled the boat out of the water I disconected a hose to drain the black exhaust manifold. Not sure if that worked or not since I haven't been back.

[bcr]

In my experince this is caused by cracked cyl head or heads,only way to know for sure is to pull them and have them checked.Sorry for the bad news.

[davinci]

The exhaust jackets are the flaps on the outside,they open out when the engine is running but stay closed when backing into the water.

[walb0244]

Can someone walk me through how the water goes through the entire system on the boat? From the water strainer intake to the exhaust flaps in the back. I don't know enough about it to know.

[Hoopskier]

If your oil is not milky and you don't see water leaking from your block or manifolds then no crack
Sounds like a riser gasket or a interior perf of your exhaust cooling jacket since your engine is running fine
Try draining your exhaust. Jackets just when you shut it off and see if that eliminates the cylinder water
.02

To me this sounds like your problem. Engine runs fine from the minute you his the water until you take it out. The water jacketed portion of the exhaust manifolds are ABOVE the head. If they are leaking internally, the water will run down the inside, backwards into the head when the engine is not running-hense filling the cylinders with water. When the engine is running the exhaust gases prevent the water from running backwards into the head. I would start here.

The flappers, I wouldn't think so. I'm assuming yours are still there anyway. A cracked head, from what you describe it sounds like alot of water. It probably be more like a hole, and the engine wouldn't run well.

[walb0244]

Is the black part that says "Indmar" the exhaust manifolds and contains the water jacket you are talking about in the above post? How do I check this for a leak? Just take it off and look for cracks? When I put this back together do I need a new gasket and if so where would I pick one of these up?

[walb0244]

Also, did compression test on all 8 cylinders because someone in here asked if I had done that.

PSI - Cylinder
185 8
165 6
190 4
190 2

220 7
150 5
170 3
180 1

Cylinder 7 has been the cylinder with water in it.

[Hoopskier]

Also, did compression test on all 8 cylinders because someone in here asked if I had done that.

PSI - Cylinder
185 8
165 6
190 4
190 2

220 7
150 5
170 3
180 1

Cylinder 7 has been the cylinder with water in it.

If your have water in #7 that would explain the higher psi. The black this that says Indmar on it is the exhaust manifold. The part attached to it on the top is the riser. Both have a water jacket around them to keep them cool. Water is pumped into the manifolds from the engine via the rubber hoses on the ends of the manifold. Water from the manifold passes up through the riser and then mixed in with the exhaust gas, then out of the boat via the exhaust system.

Being that #7 is the lowest point, explains why most of the water is there.

If it were me, I would start by draining the manifold. Take the small rubber hoses off each end to drain. Then Take the exhaust hose off the riser. Then unbolt the riser from the manifold. Start inspecting. Look inside the riser and manifold. Check the gasket as well. You are looking for signs of leaks. If you find something that looks like it was leaking, probably the part that needs replacement. These may be hard to see, or impossible, depending on the size. But need to at least check.

When you put your stuff back together you will need new gaskets. Heres a link http://www.skidim.com/products.asp?dept=1068 or your local dealer for parts.


Just to put my disclaimer on my advice. I am not a professional marine mechanic. I do have some exerience with engines. I do all my own maintainance on my own boat. This is only internet advice and I can't be held responsible for anything you do to your boat.

[DOCDRS]

my thinking is just as hoopskier is talking about........are you just getting water on the one side? if your lucky it just may be the gasket between the exhaust manifold and the riser.......vs new exhaust manifold and or new riser

[walb0244]

Yeah just getting water on the one side. Gonna start taking it apart today. Gonna start with the exhaust manifold and riser first like everyone says. Hopefully can find the problem there. Got a local marina mechanic that is normally nice enough to walk me through everything. Thanks everyone for the help will update later.