Blew 1" Hole in Exhaust Manifold -- HELP

[SPR7522]

My engine blew a one inch hole in the exhaust manifold.

I'm assuming it overheated obviously. I got stuck in a bay that was about 1 feet deep with a very muddy bottom. Took me quite a while to get out with the motor trimmed up, Making mud stew.

Started heading back to the dock and boom a one inch hole in the exhaust manifold where cylinder number three exhaust port is.

I'm wondering if I sucked in too much mud and clogged things up.

Back home now, I've cleaned out every hose and channel that I can find. I've hooked up the muffs and it appears water is going through the system and leaking out the exhaust manifold cover. The hole blew through the channel where the water runs down the side.

It will start up. I can idol it up and down, put it in gear forward and reverse and rev it up. All with water leaking out the exhaust manifold hole.

No water in the oil.

Did a compression test.

Cylinder 1 ---195
Cylinder 2 ---195
Cylinder 3 ---160
Cylinder 4 ---195

So definitely something happened in cylinder 3. That's where the whole lines up that blew in the exhaust manifold cover.

Any ideas how much damage I could have?

Can you just replace one piston? Or do you have to redo the whole engine?

Do you think anything else's wrecked?


Thanks in advance for any help or suggestions

 

[robert graham]

Any info on the motor type, year, model number, etc. would be helpful....

 

[99yam40]

good chance it is not a Yam or suzuki outboard motor with a exhaust manifold

 

[robert graham]

He mentions "no water in the oil", so must be a 4 stroke?....great guessing game here!....

 

[SPR7522]

1999 Suzuki DF70 Four Stroke

 

[SPR7522]

PIC

 

[99yam40]

need to take it apart to see what happened.
did the hole melt out or did something come through there and knock a chunk out

 

[SPR7522]

I'd say it melted through. It melted through the water channel of the cover, so 1/8 then 3/8" space (where the water should be running through and the outer 1/8"

I've cleaned ever hose and outlet that I can find and now with muffs water comes out the manifold through the channel in side and out the hole. If there was no hole it would come out the tell tale hole now.

I'm sure it was the mud i went through plugged things up and let it over heat. it had to heat up the inside of the water channel and the outside wall. So, my guess no water inside the manifold tubes.

 

[SPR7522]

But, all that being said some thing getting shot threw, making the hole is something I have never thought of.

Any ideas what that could have been?

other if I run the engine with the muffs on water spits all over the place coming out the whole. I'm sure that what cause me to find water on plug 3 and 4.

I can start there engine(with out water), it run great, idols smooth for short 10-15 sec. test

 

[99yam40]

not really

need to open up and see what kind of damage you have to figure out what happened and what needs to be done

 

[mjf55]

Stop running it without water as you are killing your water pump. Also I would suggest covering your compression thread in this one so you can handle all your issues in one place. The low compression in Cylinder 3 does matter and is indicative of a problem.
Do what 99yam40 suggests and start taking it apart. You will need a service manual to help guide you.