Water in exhaust (wrong place)

[mb7]

Today I put in water to figure this out. So, like always, run nice for 45 min and starts to run rough and dies .
I got the spark plug for the piston #4 and had water in it . All the others was fine.
Back home removed the oil no water
Removed the exhaust elbow and had water inside the exhaust portion (bigger Hole)
My question is how the water got into the piston #4 ?
Would all the other pistons blow the water through the exhaust valve ?
Can the manifold be repaired? or new one $$$$$



3.0 mercruiser 1986 alpha 1 gen 1

Thanks for all of you guys
This forum is the best, so much info.

 

[Bt Doctur]

Re: Water in exhaust (wrong place)

either the manifold or riser/elbow has a hole thru it.

 

[mb7]

Re: Water in exhaust (wrong place)

Thanks for your quick reply

Is it a way to test the riser?

 

[linkman]

Re: Water in exhaust (wrong place)

The riser can be tested for internal leaks, but if yours is the original fit, and if the boat has always been used in ocean (salt) water, it would be better to simply replace it. They typically cost about $100 each. I had water in 4 cylinders on a V-8 that resulted in corroded valve stems and bent push rods. The repair man told me risers only last about 4 years in salt water.

 

[mb7]

Re: Water in exhaust (wrong place)

I just bought new manifold and riser, but i didn't got the mercruiser.
Is GLM ok, or should I returned?

 

[mb7]

Re: Water in exhaust (wrong place)

Please Help!!!!!!

I put the new manifold and riser yesterday, looks good!!!!
I decided to a test, so at the river starts right up, runs nice and quiet .....

I notice the wot was 3 mph lower them before. 35 at 4600

Slow down, with the engine idle, I can hear ,not loud, knocking from the middle bottom of the engine and sometimes go away. Engine runs rough in idle, but if I give gas runs good.

Check the plugs was clean and light tan color, remove spark wires one at the time while running, doesn't appears to be an specific cylinder.
After few minutes running rough dies and sometimes starts, but continuos run rough

The engine came with electronic ignitor and flame thrower coil 3 ohms (pertronics)
New cap, rotor, wires, spark plug and rebuild Carb.

Back at home compression test

1 = 120
2 = 122
3 = 120
4 = 115

Oil is clean, and I add some rislone before the test 1qt after removed 1qt of oil

thanks everyone...

 

[mb7]

Re: Water in exhaust (wrong place)

Please, Please, Please

Guys Help me!!!!!