87 Sorrento 19

[rodfarm]

Hi After reading a few things both on here and in the manual I believe I have an idea of what happened last weekend. Recap: We bought the boat last winter and just got it out over the weekend. I had run it on the muffs to make sure everything was allright, no apparent problems on Saturday. It ran fine for about 10 got up to 140* so I shut it down and went on getting ready. Sunday we unload idle around while the wife parks the truck, pick her up from the bank and head out across the lake. Boat takes off well, gets up on plane quickly and I think this is going good. I then look down at the temp and see it climbing a little over 215 so I shut it down and go to look at whats wrong. With the engine cover up the engine seems fairly warm but not bad, the large waterpump hose is firm like it is pressured up. I think maybe the thermostat is stuck so I will let it cool a little and head back to look deeper. After a few I try to start it and the starter turns very little before it seems like it meets resistance but won't turn all the way over. I now think the worst that I fried the motor then that doesn't make sense because it wasn't that hot. So after reading alot, here's me diagnosis: The impleller didn't work while up on plane (30-40 seconds at most). I then shut it down and the surge went up past the now slightly crisped flappers and in to a cylinder or two causing the hydro lock. Now my question, can I just drain the oil, pull the plugs and turn it over a little to blow any water out. Replace the flappers, double check flow path while I'm at it and hopefully go on and enjoy the summer?

Thanks

 

[revlimiter776]

what is your ignition timing set at? DID YOU HEAR ANY PINGING UNDER A LOAD? the hydro lock seems a little far fetched for mr right now, hot motors dont like to turn. do a compression check and if all is good time your motor, old gas also causes pinging, from low octane #s, i would also be concerned about the car being lean is it a quadrajet by any chance? the are notorious for being lean good luck

 

[rodfarm]

Update: I had pulled every thing apart and blown the water from the cylinders, it had filled at least two of them. The motor didn't get hot enough to hurt anything as Rev assumed above. It must have been enough of a wave back surge pressure and I didn't help anything by killing the motor before we had come to a stop. Therfore no exhaust to keep the water from backing up the exhaust and into the manifold.

We made a second trip out after replaceing the impeller and still have a heatiing issue. So I pulled all the raw water lines off and back flushed down through the power steering cooler with the impeller housing on the outdrive off, and I got quite a bit of loose flakes and crud out that way. While I had the impeller off I decided to hook the hose straight to the motor and bypass the lower unit. I ran it with full flow for 5-8 minutes it came up to temp the exhaust manifolds were only warm to the touch and it stayed at 170*.

The thing that I don't know about but seems odd is, The water and exhaust flow that comes down from the exhaust manifolds exits from the front of the housing near the space behind the anode. Is this normal or should it come out the center of the prop? Does this mean I have a blockage behind the prop, and at speed there is enough force from the water to keep the ehaust flow and return water from making it out?

Thanks again