Restricted Raw Water Cooling Flow?????
 

Greetings,

Subject vessel is a 1985 Sea Ray 300 Weekender with twin 260
Mercruisers. Engines have full fresh water cooling.

My starboard engine is overheating, and at cruise I noticed that the
flow of cooling water coming from the exhaust is significantly reduced
as compared to the port side.

What I've checked/done so far:

1. Through hull water pick-up clear, valve fully opened
2. Strainer basket clear
3. Impeller checked
4. Heat exchanger serviced

From what I can tell, the only other two points of possible
restriction would be at the riser (manifolds are fresh water cooled)
or the transmission cooler. Before I break out the wrenches, are the
transmission coolers copper based? Is it more likely that the
restriction would be at the riser, or at the transmission cooler? Am
I missing another area of concern?

Thanks!

Subject: Restricted Raw Water Cooling Flow?????
From: (Seadweller)

Before I break out the wrenches, are the
transmission coolers copper based?

Many are.

Is it more likely that the
restriction would be at the riser, or at the transmission cooler?

Based on the age of the boat, I'd say riser.

Am
I missing another area of concern?


Collapsed hose/s perhaps.

Get a laser guided temp. reading gun.
With that you should be able to pin point the area of restiction.

Capt. Bill

Risers gets my vote. How old are they? You might be looking at getting all
4.

"Seadweller" wrote in message
...
Greetings,

Subject vessel is a 1985 Sea Ray 300 Weekender with twin 260
Mercruisers. Engines have full fresh water cooling.

My starboard engine is overheating, and at cruise I noticed that the
flow of cooling water coming from the exhaust is significantly reduced
as compared to the port side.

What I've checked/done so far:

1. Through hull water pick-up clear, valve fully opened
2. Strainer basket clear
3. Impeller checked
4. Heat exchanger serviced

From what I can tell, the only other two points of possible
restriction would be at the riser (manifolds are fresh water cooled)
or the transmission cooler. Before I break out the wrenches, are the
transmission coolers copper based? Is it more likely that the
restriction would be at the riser, or at the transmission cooler? Am
I missing another area of concern?

Thanks!

"Seadweller" wrote in message
...
Greetings,

Subject vessel is a 1985 Sea Ray 300 Weekender with twin 260
Mercruisers. Engines have full fresh water cooling.

My starboard engine is overheating, and at cruise I noticed that the
flow of cooling water coming from the exhaust is significantly reduced
as compared to the port side.

What I've checked/done so far:

1. Through hull water pick-up clear, valve fully opened
2. Strainer basket clear
3. Impeller checked
4. Heat exchanger serviced

From what I can tell, the only other two points of possible
restriction would be at the riser (manifolds are fresh water cooled)
or the transmission cooler. Before I break out the wrenches, are the
transmission coolers copper based? Is it more likely that the
restriction would be at the riser, or at the transmission cooler? Am
I missing another area of concern?

Thanks!

If you can check the tension on the raw water rubber hoses before and after
they go into the different RAW water cooled units you might be able to find
the restriction. The problem cooler will have a rubber hose going into it
that is harder than going out.