Universal M-25 Cooling System

[Steve Treppa]

Can anyone tell me what the physical layout of the raw water cooling system is on a 86 Catalina 30 with an M-25 engine?I've run pink stuff through the engine but never got any out the stern. Is there a thermostat?There is definitely pink stuff in the muffler....I'm assuming that's pretty much the end of the line anyway...am I winterized? I've got about 2 gals. in the system.

 

[Mark Johnson]

2 gallons?

2 gallons should be more than enough to pump through the engine and have it come out the exhaust. Did you pump it through the raw water intake to the engine?? Have you checked the antifreeze on the fresh water side of the engine? Is it good to about 20 or 30 below? The thermostat controls the water flow on the fresh water side of the engine only. MPJ

 

[Kevin McGrath]

M-25 Cooling

I have the same boat and 2 gallons was enough to winterize the system.In order to put through as much antifreeze as possible I drained fresh water out of the raw water side out before I ran the motor with the anti-freeeze. I had pink antfreeze coming out in ten seconds.

 

[Mark Gale]

Pink

I disconnect the intake from the raw water and put anti-freeze in with the engine running. I start to get it out the back before the first gallon is done and use the second as a back-up. 2/3 through the second gallon, I loosen the seacock on the muffler (access is through the engine door near the galley) and let a little trickle out there.Are you sure you went on the intake side of the raw water hose? You could be dumping it out the bottom of your boat.

 

[george goodall (georgeg305@aol.com)]

raw water system

you asked for a ph;ysical description of the raw water system on a cat 30/m 25. Here it is on my 86 model cat 30. Starts with the thru hull valve located a foot or so to port of eng., strainer mounted on valve. Hose to raw water pump mounted on front of engine. pump is about size of your fist. Output of pump is hose: runs alongside of enge to heat exchanger (tube about size of summer sausage) mounted on rear of engine. output of heat exchanger is hose loops up into storage cabinent under sink, goes to anti-siphon valve then down and dumps into to exhaust pipe just above muffler. Water lift Muffler is white box just to port of rear of engine. Water builds up in muffler until exhaust gas pressure blows it out the exhaust pipe. Exhaust pipe is large diameter rubber hose. runs to back of boat on port side: thru cockpit lazerete, then cross over to fitting on stern. Note that raw water never goes into the engine.