water in cyclinder

[ferryrat]

Have a 74 SeaRay 24 foot with a 302 and TRll stern drive. Had a rebuilt motor(long block) put in last year and converted to fresh water cooling. Engine has about 25 hours on it. I went to start it up and let it crank over a bit to get the oil going and gas to the new carb. I have a sea water shut off valve in line with the sea water pump, so I can hook up a garden hose to flush the engine. After two tries I heard a loud bang like something broke inside the engine and after that the engine would not turn over. I took it back to the shop that did the work. He said that water was in the cyclinders and want to know if I left the valve open while flushing and no I don't. According to a Clymer book you are suppose to close the valve so this is the way I do it. Did it that way all last year with no problem. There was a good water flow out the two ports by the transom and water coming out the exhaust threw the prop. Is there a way for water to get back to the cyclinders?

 

[Haut Medoc]

Re: water in cyclinder

Welcome to iboats.. Water or anti-freeze? Since there several different configurations for the cooling set-up on your motor its hard to say, and you added an after market fwc assembly I assume. Are the manifolds now part of the raw water system or the closed system? I don't see how water could get into the cylinders, unless you have a cracked, porous/manifold ,riser or cylinder block.....J

 

[ferryrat]

Re: water in cyclinder

He said it was water. The manifolds are part of the closed system and the manifolds are new.

 

[Haut Medoc]

Re: water in cyclinder

Are the risers new?

 

[tommays]

Re: water in cyclinder

if you have to much flushing water and the motor is not ON it could back up it depends on how free flowing the exaust is bellow the elbows<br /><br /><br />tommays

 

[ferryrat]

Re: water in cyclinder

Not sure if risers are new.

 

[ferryrat]

Re: water in cyclinder

For tommays, what would you consider as to much water pressure?

 

[tommays]

Re: water in cyclinder

its more flow rate <br /><br />when the motor is running and pumping its own water there has to be something wrong to cause a problem<br /><br />when people make DIY flushing systems there more things that can go worng if the boats in the water <br /><br />if you have spring closed exaust flappers like this<br />

<br /><br />they will restrict water flow when the motor is off if you have a high enough water flow it could back up the y-pipe<br /><br /><br />tommays

 

[Haut Medoc]

Re: water in cyclinder

Was the boat in the water when this occure...J

 

[ferryrat]

Re: water in cyclinder

The boat was sitting on the trailer in my driveway. I had flushed the system this way about ten (10) times last year with no problem.<br /> Thanks