Over Hill Sailing Club
Join Date: Feb 2009
Location: Adirondacks NY
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Re: Yanmar 2GM20F Coolant
If your exchanger is clogged, it may be the cause of the overheating and lack of water flow. As mentioned, check the outside strainer cap, then the valve, then any inside strainer, right up to where the hose enters the pump. Check the impeller again. If still in doubt, start/stop the engine quickly with the hose off the downstream side of the pump to see if the thing is pumping. If it is, that narrows it down to flow through exchanger and riser. The riser is easy enough to check by just blowing through it. If the riser is clear then it's time to clean the exchanger.
The water enters the boat through the seacock. That almost always has an outside strainer which can get slogged from seaweed, etc. Once through the seacock, there can be another inside strainer which looks like a clear cylinder or a saucer-like device. That may be clogged if you have one. From that filter, the water goes to your seawater pump and then to the engine.
Alberg 35: With a philosophical flourish Cato throws himself upon his sword; I quietly take to the ship.
Last edited by smurphny; 06-14-2015 at 03:00 PM.