water fountin in the boat

CTD

Petty Officer 1st Class
Joined
Nov 13, 2002
Messages
234
Re: water fountin in the boat

When you find the answer we will all say "why didn't I think of that". Hopefully cranking it over with the water on and the plugs out will give you an answer.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: water fountin in the boat

If the valve timing is (seriously) out, then the exahust valves will still be open when the piston is going down (sucking water in) and the intakes will be open as the piston is going up (blowing the water out through the intake manifold/carb). Did you say that you had just pulled the engine down and rebuilt it? <br /><br />The reason for it not doing it on the flushers is that there isn't enough water in the exhaust system. When the boat's in the water the bottom half of the exhaust tubes are full and any sucking will pull water in. <br /><br />Just a thought.<br /><br />Chris.................
 

djvan

Chief Petty Officer
Joined
May 3, 2003
Messages
411
Re: water fountin in the boat

Does your setup have exhaust shutters? If so take a look at them. I don't know if this could cause that much water to enter or if it would enter while just on the trailer. Just thought since nobody else mentioned it I would, good luck.<br /><br />DougV>
 

FreeBeeTony

Captain
Joined
May 15, 2002
Messages
3,995
Re: water fountin in the boat

If the timing was that far off...........would it still run?
 

Elk Chaser

Petty Officer 2nd Class
Joined
Jul 29, 2003
Messages
186
Re: water fountin in the boat

The timing chain would have to be what, near 180 degrees off to allow the exhaust and intake valves to work opposite of normal.........<br /><br />That would explain it. <br />I suppose it could have messed up the last time it ran, jumped teeth or something but 180. :confused: <br /><br />Have you checked the timing chain and gear alignment? <br /><br />Here's hoping you caught the water fast enough without causing any other damage, if the timing chain did jump off then that would have saved the motor. :D
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: water fountin in the boat

It wouldn't need more than about 20 degrees, and yes it would run.<br /><br />Chris........
 

CTD

Petty Officer 1st Class
Joined
Nov 13, 2002
Messages
234
Re: water fountin in the boat

I'd go with the valve timing too except for the part where he said he let it run and then took it to the lake where he had the same problem. I guess it could be cranking backwards too.
 

klopfelter

Cadet
Joined
Jul 25, 2004
Messages
7
Re: water fountin in the boat

I am having the same problem except with a different engine. I have an aq125. The boat had been running great all day, we stopped for a final swim on the way to the marina and when I turned the key to go home water shot out of the carb. Its been three weeks now and the mechanic still doesnt know what is wrong with it.
 

tryan

Seaman
Joined
May 29, 2004
Messages
59
Re: water fountin in the boat

my 0.02<br /><br />351 manifold on a 302?<br />motor is turning backwards?<br />manifold to riser gasket?<br /><br />you said you replaced the manifold, what about the riser?
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
13,995
Re: water fountin in the boat

How do you launch the boat? Do you back the trailer just a bit leaving the boat up out of the water, then give it a mighty shove and let it roll off the trailer? Or do you back up rapidly, slam on the brakes letting inertia launch the boat? Either of these ways can allow water to be pushed up the exhaust and into manifolds and eventually the cylinders. Since there is a period when the intake valve has opened before the piston reaches TDC water could be blown out the carb.
 

baddog00100

Cadet
Joined
Aug 18, 2004
Messages
10
Re: water fountin in the boat

hay guys thanks for all the input i have metal chan and gears if it did slip should't i have heard so knocking and pinging if it did and it would have cut off on its own due to miss firing wouldn't it? as i said in my first post it was running great all day and after i cut the engine at the final spot is when it wouldn't start and when i turned it over the water came out of the carb. i don't have shutters on th exaust and i didn't replace the risers. they look good and i can't see that just backing it into the water would or could push it that far up. i never had the problem any other time i put it in so why should it start all of a sudden. even when i'm on the water comming to a stop i let it idel for about a minute or two before i cut the engine. secse this first started i haven't had it off the trailer sense. i stare try to stare it on the trailer but the engine and risors are above the water line. the theroy about the timing makes some sense i will look at that this afternoon. thanks again
 

pine island fred

Lieutenant Junior Grade
Joined
Dec 20, 2002
Messages
1,144
Re: water fountin in the boat

looks like big bird-20 is starting to have the same problem as you. my distant thinking is that the intake manifold ( cracked ) is the problem. good luck,let us know your progress. fred
 
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