First, see if the volumetric output .... (the water coming out at the
exhaust hole at the back of the boat) is within 'spec'. That will be
found in your owners maintenance manual; and, will be something like:
3 gallons per minute at 2500 rpm. You measure it with a bucket and a
stopwatch. If the that flow is not correct, then look for a
restriction in the system such as broken impeller vane lodged in the
rubber hoses, large rust 'flake' breaking loose inside the exhaust
manifold (common occurance), etc. etc. Old cast iron exhaust
manifolds have the 'habit' of breaking off huge 'slabs' of rusted cast
iron inside the manifold passages that will restrict the water flow.
If the volumetric flow rate is within or near spec. then Marsolve or
Rydlyme will work wonders in descaling the exchanger and the engine
internals. Use it on both cooling circuits: the raw water side and
the fresh water side.

Check for a flow restriction with a bucket and a stop watch FIRST. ;-)


In article , Rick & Linda Bernard
wrote:

Anyone tried it? I have a question in on their web site but they don't seem
to want to answer it.

Let me poise the question to the group -

I have a 50 hp fresh water cooled diesel that is beginning to run hot. The
engine temp seems to be creeping up to 200 F at cruising speed with salt
water temps in the 60's. Used to run at 180-185 with water temps of 80+.
Water flow out the back seems less then expected and has been going down
over the years even with a new raw water impeller-pump.

Without pulling the heat exchanger, exhaust elbow, and hydro lift out can
Marsolve clean up the system? Marsolve is $20 a gallon and I am willing to
pay vs having to pull the heat exchanger and elbow. (need to pull the heat
exchanger to get enough room to get the elbow. In fact I might need to pull
the exhaust manifold)