Rubber exhaust Pipe fire

[Raider316]

2000 Bayliner I/O 5.0 Mercruiser

Took boat out and ran it for an hour or so.
As I slowed down smoke was rolling from the engine compartment. Apparently the rubber exhaust pipe on the exit side of riser was burning up. i cut it open but never saw flames but used fire extinguisher anyway.

The riser on that side was definitely hotter than the other side.

Engine temp was fine at 175 degrees.

Once it got towed back in. I test started it and it started up fine.

No water in oil engine

That's when I noticed the missing plug on the top of the exhaust manifold.
Could that have been the problem all along? Water was definitely coming out of it.

I have uploaded both sides of engine for reference

Any suggestions/ help would be appreciated.

 

[alldodge]

Could that have been the problem all along?

Have you been having troubles, if so what kind?

Yes with the plug gone there would be exhaust getting hot, water in the bilge,

 

[Bt Doctur]

must have had a lot of bilge water. Doubtful it fell out and there is no reason to remove that plug in the first place

 

[Raider316]

Have you been having troubles, if so what kind?

Yes with the plug gone there would be exhaust getting hot, water in the bilge,

Thanks for the response. No problems at all. It was running pretty good.
Never realized I had a problem til I came to a stop.

 

[achris]

Pretty likely the exhaust shutters are fried.

 

[tpenfield]

Oh boy, what a mess you made . . . :)

Looks like you should . . .

Replace the missing plug on the manifold

Replace the rubber boot on the elbow

Replace the exhaust 'flapper' inside the exhaust tube.

Don't do it again

 

[Lou C]

Mystery is WHO removed that plug, they usually don’t come out by themselves and that’s not a drain plug obviously!

 

[Raider316]

Yes it is!

 

[GA_Boater]

Mystery is WHO removed that plug, they usually don’t come out by themselves and that’s not a drain plug obviously!

Yes it is!

No longer a mystery. But there is another mystery - How does water drain up hill?

 

[tpenfield]

No longer a mystery. But there is another mystery - How does water drain up hill?

Must be for boating in Australia . . . achris any word on that :noidea: I know the water in the toilet spins the opposite way in the southern hemisphere . . .

 

[Raider316]

No longer a mystery. But there is another mystery - How does water drain up hill?

My response was intended for the comment that it was a mystery not that it was a drain plug.

 

[achris]

Must be for boating in Australia . . . achris any word on that :noidea: I know the water in the toilet spins the opposite way in the southern hemisphere . . .

:facepalm:

 

[JASinIL2006]

Poor Chris... having to deal with all the southern hemisphere jokes...

 

[Scott Danforth]

Poor Chris... having to deal with all the southern hemisphere jokes...

ʍou ʎq ʇᴉ oʇ pǝsn sᴉ sᴉɹɥƆ 'ɥɐN

 

[JASinIL2006]

ʍou ʎq ʇᴉ oʇ pǝsn sᴉ sᴉɹɥƆ 'ɥɐN

:lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol:
:lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol:
:lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol:

 

[achris]

ʍou ʎq ʇᴉ oʇ pǝsn sᴉ sᴉɹɥƆ 'ɥɐN

Never gets old, does it? :thumb:

 

[Scott Danforth]

Never gets old, does it? :thumb:

I have the mental maturity of a 3 year old......so no....lol....love ya Chris.

 

[Raider316]

UPDATE
Had time today to look at boat.
-All the rubber exhaust tubes on that side of engine are toast
- The mystery of the plug is solved. It basically melted and was blown out.

- the exhaust flaps are missing.

My question is could the flaps be lodged further down exhaust tube and clogging up exhaust? Maybe cause of all the problems?
I stuck a hose down the exhaust pipe but water did not back up.

I intend to replace manifold, riser and of exhaust flaps.

Ultimately I am concerned about the missing flaps and where they are.

 

[Bt Doctur]

The mystery of the plug is solved. It basically melted and was blown out. Well ,if it got hot enough to melt cast iron you have bigger troubles

 

[Raider316]

The mystery of the plug is solved. It basically melted and was blown out. Well ,if it got hot enough to melt cast iron you have bigger troubles

Plug was plastic
Engine is running fine outside of the overheating riser