787 crankcase filling with water

[gcha1727]

Any input is greatly appreciated..

After dropping the boat in the water I started both motors. Maybe a minute or two later the starboard motor stalled and wouldnt restart. I left the lake and found the water in the motor. I pulled the plugs and blew it out and now it starts again.

I checked all the water lines for obstructions/blew them all out. None of them appeared to have anything blocking them. Im pretty certain that nothing is fixed and am unsure what to look for next.

What could be causing water to get into the motor or prevent it from circulating out???

Thanks

 

[Phildoo]

If its comin in that much, drop in in and look visually. Check you bilge fuse.

 

[Phildoo]

I misread that. Was thinking your bilge area was filling with water.
Have you done a compression test?

 

[gcha1727]

Yes. I have compression tested and am just under 150 psi in each cylinder. I did have some water coming in but nothing my bilge pump couldnt easily remove.

 

[Phildoo]

Only thing I can think of is a bad head o-ring or possible cracked jug.
I'm sure other guys will chime in here soon.

 

[djredman99]

Did you continue to drive the boat after the first engine stalled?

If you went above 15 mph with a stalled engine, you could have force water from the cooling system back into the dead engine. You have to clamp off the intake cooling line if you want to run it on one engine. Same applies even if you get towed, then you have to do it on both engines.

So, your stall could have been cause by something completely unrelated to the water. The water could just be from driving the boat back on one engine.

 

[gcha1727]

Thanks for the responses..

I did not drive the boat. I never left the dock. While letting the motors warm and still at the dock was when it stalled.

As far as the possible o-ring being bad, what should I look for ???

I did take the head gasket off and the 2 small o-rings were there around spark plug opening along with the the big o-ring that goes around the head gasket.

Any other ideas???

Thanks

 

[BMANN06]

Have a look at the drain tube, it's a little hard to get at with Exhaust Header in way, but there is a line from each jug that goes to a T fitting that then goes to back of pumps to drain out. This line is near bottom of jugs on exhaust side, it may be plugged not allowing the cylinders to drain. Other than that there are several seals under cylinder head cover you may have a leak in there or a cracked jug. DJRedman makes a point too .. how long did you have them running at dock, then how long did you have the working engine running before shutting it off?

 

[gcha1727]

Thanks for the response..

I did check all the water lines including the drain tube and did not find any obstructions.

As far as run time at the dock;

The problem motor ran for maybe a minute or two before stalling. After that I did try to restart off and on for maybe 20 minutes without success.
As far as the good motor I did have it running most of the time. I did shut it off a couple times and restarted but it was running for most of that time.

I did see 5 gaskets when I pullled the head off, They appeared to be fine but cant say for certain.

I did not check to see if the jug is cracked yet but do have good compression.

Is it possible to have blockage within the exhaust causing a backfeed into the motor???

Any other thoughts??
Thanks

 

[BMANN06]

Tighten up the cylinder head and do a compression test. This will give us some useful info, post back with compression test results.

 

[Phildoo]

Yep. Your on the right track...