over heated exhuast port

[treeman]

i have a 350 inboard volvo and we ran around all day everything was fine then i noticed smoke pulled the cover off and if your looking at the motor on the right side the big hose that comes from the exhuast was starting to smoke i shut it off pulled the plug on the back of the exhuast let it drain then fired up the motor and it seemed to pump plenty of water iam not sure what happened could anyone please addvise thanks tree

 

[rodbolt]

Re: over heated exhuast port

either your seawater pump is failing or the riser is clogged, or both.
the exhaust is water cooled, for some reason your not flowing enough out of the riser to cool the exhaust downstream.
its not uncommon to have one riser clogged and enough flowing from the other to keep the engine cool.

 

[treeman]

Re: over heated exhuast port

how do i fined out if this is it the inboard motor is new to me iam still learning the ropes

 

[treeman]

Re: over heated exhuast port

what or where is this riser located thanks tree

 

[treeman]

Re: over heated exhuast port

how can i tell if my sea pump is working right

 

[Don S]

Re: over heated exhuast port

what or where is this riser located thanks tree

The risers set on top of the exhaust manifolds. Since you had smoke rolling, I would be you have also lost the hose (4" dia) at the back of the riser to the exhaust Y has burned up and will need replaced
Water has to flow thru the exhaust system to cool it. IF they get plugged from rust they need to be replaced. If the manifolds are also plugged up, they need replaced also. DO NOT try to do just one side. They must be replaced in sets.

 

[rodbolt]

Re: over heated exhuast port

Ill let DonS explain it, he can also post pics, my poor machine just wont. one day I may replace it.
but after working yesterday, then towing a commercial guy in with 35 MPH sw winds and working this morning my red dots are sore.
keep bumping this and we can walk ya through it, but today my brain is simply to tired

 

[Don S]

Re: over heated exhuast port

morning my red dots are sore.

LOL

 

[treeman]

Re: over heated exhuast port

today i tried it again and i noticed that the hose swelled up ok so ill take off the risers then can they be cleand and what do you sugguest to use for that and why is the hose bad becuase of to much heat it does not leak ??? iam new so please be kind lol. thanks tree

 

[Don S]

Re: over heated exhuast port

If they are plugged up, that is the final warning from your manifolds and risers that it's time to replace them. The next step down the road of problems with them would be cleaning them and having water getting into the engine and destroying it.

What you need more than anything else right now is the Volvo OEM service manuals for your engine and drive. So far all we know is that it's a 350, not a lot of help, as there has been many changes over the years.
What is the year and full model numbers of your engine and drive??????

 

[treeman]

Re: over heated exhuast port

i also took the hose off that goes to water pump on front of crank i was told this is the sea bridge pump???? and water flows through it all the way out to the 2 hoses located at the bottom out side of the volvo out drive would this not mean the system is flowing free ??? thanks for all your help guys i do appreicate it thanks treeman

 

[treeman]

Re: over heated exhuast port

how do i get that info the moteor was a 225 hp volvo and the put in a 350 long block the boat had no manauls its a 1986 bayliner model 2150 is all i know thanks treeman

 

[Don S]

Re: over heated exhuast port

water pump on front of crank i was told this is the sea bridge pump????

It's known as either a Seawater pump, or a raw water pump. Never heard one call a sea bridge pump.

water flows through it all the way out to the 2 hoses located at the bottom out side of the volvo out drive would this not mean the system is flowing free ???

The water coming out both hoses on the drive only means some water is making it to the back. Probably all thru the starboard manifold since the Port manifold overheated. The hoses on the transom shield are connected inside and water from one side will go out both.

the moteor was a 225 hp volvo and the put in a 350 long block the boat had no manauls

It was probably an AQ225D, which Volvo used up to 1986. You can go to the link below and type in the AQ225D into the Engine Type box and download a free owners manual. It will give you a lot of information you need to understand your engine and drive.
http://www.volvo.com/volvopenta/glo...ice/publication_search/publication_search.htm

 

[treeman]

Re: over heated exhuast port

again thanks don and i took off riser and it was clean i think the hose was clamped to close to the grooves that let the water out of riser being you can see the inprint in the inside of the hose i think that would give it enough restriction not to let the water flow right what do you thank manifold is clear also can not find anything else that would cause this thanks much