97 Mercruiser starboard exhaust really hot

[lowvlot]

I have a 97 blue water Monte Carlo I just put an engine into it last year. I put it on the muffs and ran water through it yesterday. At first I had no water at all cycling through. I turned up the hose and got water. However, the starboard side exhaust is really hot while the port side is not. I've done some searching and it seems this is a common problem. Some saying that it is normal and others saying anything from water pump impeller to blockage in the cooling line. So, I am coming to you guys for assistance.

 

[thumpar]

How hot? Can you keep your hand on it?

 

[Bt Doctur]

If we knew what engine and what drive we might be able to answer better

 

[lowvlot]

How hot? Can you keep your hand on it?

no I can't even touch it without being burnt

 

[lowvlot]

If we knew what engine and what drive we might be able to answer better

sorry.
It is a 350 V8 Mercruiser with an Alpha one.

 

[thumpar]

It sounds like you have a clogged elbow/manifold. How old are they?

 

[Bt Doctur]

A quick test, remove the hoses and try to blow air thru them. should be no resistance blowing thru them with mouth pressure

 

[JoLin]

It sounds like you have a clogged elbow/manifold. How old are they?

Sounds like it to me too. You said you 'put an engine in it last year.' What does that mean? Were manifolds and risers changed? Is the boat fresh water cooled or raw water cooled? Is it used in salt?

It's normal for a GM small block (including the V-6's) to runner warmer on the starboard riser than the port, but neither side should be uncomfortable to the touch.

 

[lowvlot]

It sounds like you have a clogged elbow/manifold. How old are they?

the boat is a 97. I'm guessing they are original

 

[lowvlot]

A quick test, remove the hoses and try to blow air thru them. should be no resistance blowing thru them with mouth pressure

would these be the hoses that come off the water pump? There should be no resistance at all? Even if I have run water through the engine? Forgive me, I know nothing

 

[lowvlot]

Sounds like it to me too. You said you 'put an engine in it last year.' What does that mean? Were manifolds and risers changed? Is the boat fresh water cooled or raw water cooled? Is it used in salt?

It's normal for a GM small block (including the V-6's) to runner warmer on the starboard riser than the port, but neither side should be uncomfortable to the touch.

No the manifolds and risers were not changed. It is cooked by lake or river water. Fresh water only

 

[thumpar]

No the manifolds and risers were not changed. It is cooked by lake or river water. Fresh water only

When he mentioned fresh water he was talking about the cooling system. Does it run antifreeze or only water from the body of water?

 

[bruceb58]

Last time impeller was changed?

 

[lowvlot]

When he mentioned fresh water he was talking about the cooling system. Does it run antifreeze or only water from the body of water?

just water from the body of water

 

[lowvlot]

Last time impeller was changed?

I do not know this answer

 

[thumpar]

If you don't know it has been too long.

 

[bruceb58]

If you don't know when your impeller was changed, change it and see what happens with your exhaust temps. Since the flow to each exhaust is not exactly equal, you could be getting just enough water to keep one side cool and the other side has a completely inadequate flow to do much at all.

 

[lowvlot]

What is involved in changing the impeller in a alpha one

 

[thumpar]

Pu it in forward, remove 6 nuts for the drive, pull the trim pin. The drive will come off. Then you split the drive and remove the impeller housing. It is a good idea to pull the drive at least every other year and change it while you lube and check everything over. The first time it might be a few hours to do but once you get it down it goes faster.

 

[Bt Doctur]

If you have hoses at the blue arrows, plug them for testing