2002 mercruiser 5.0L Question

[bone354]

A friend of mine has a 2002 5.0L Mercruiser Alpha One {serial # 0m007668} Raw water cooled . He had the manifolds and risers changed this spring and one of the risers is hotter then the other it is around 190 degrees measured with temp gun on top of riser. The mechanic says this is normal for this engine that it has a tube coming from the intake manifold area to the exhaust manifold on this side. Does this sound right and what is this tube for. The engine temp is fine and no alarms go off. It is just hot compared to the other side. Thanks in advanced . Rich

 

[Fun Times]

A friend of mine has a 2002 5.0L Mercruiser Alpha One {serial # 0m007668} Raw water cooled . He had the manifolds and risers changed this spring and one of the risers is hotter then the other it is around 190 degrees measured with temp gun on top of riser. The mechanic says this is normal for this engine that it has a tube coming from the intake manifold area to the exhaust manifold on this side. Does this sound right and what is this tube for. The engine temp is fine and no alarms go off. It is just hot compared to the other side. Thanks in advanced . Rich

That's to hot, Yes the starboard side runs hotter with that tube, But not that hot. It's somewhere around 20ish degrees hotter normally then the other side.

My first guess would be one of the gaskets between the manifold and riser is either the wrong style or installed wrong.

You do have a 3 inch riser correct?

Or it could be a clogged manifold or a bad manifold from new, ect.

What name brand is the new manifold?

 

[bone354]

They are new merc parts and it has the spacer I will try and post pic later. Thanks Rich