Yanmar 2GM - draining

[HappyHunter]

The manual with my 2GM is pretty hopeless, as hardly any important parts are named in the drawings. As I am keeping the boat in over winter, I want to know how to drain and flush both the salt water and fresh water parts of the cooling system, but haven't got a clue how to do this.

At the rear of the engine, on the starboard side (the exhaust side) there is a little metal tap with a plastic tube running from it. I turned it and drained a little fluid out. It looked slightly rust coloured and tasted a bit salty, so I find it difficult to know whether this was "fresh" water or salt.

As I have a plastic expansion tank, I assume that I do not have to drain this.

One further question: I have an electric immersion heater in the calorifier. It seemed to me that this might well keep things warm in freezing weather, but is it likely to do any harm to have it cycling on and off permanently for a couple of months.

Any help gratefully received, as ever.

 

[snowleopard]

taps at the bottom of the block drain the water jacket which is fresh water on the 2GM20(F) and salt on the raw water cooled engine. my engines are the latter version so i don't know about the salt water side of your engine but if you can't find a tap, disconnect the lower hose from the raw water pump or the seacock.

if you want to leave the immersion on, do yourself and your bank manager a favour- remove the cover from the heater and turn the thermostat right down- it's probably a little white disc with a slot in it.

 

[Guest]

if you have a fresh water cooled engine, the water you tasted should have had the flavour of ethylene glycol - you know, the stuff that the French have been known to add to their wines.Salt suggests some sort of leak in the heat exchanger. Your sense of taste to salt is quite accute so you should check this point out. You also need to make sure that the fresh water circuit is topped up with anti freeze mixture after the bit you drank.

I wouldnt be inclined to leave the fresh water tanks, pipes etc full over the winter unless you are v confident of the coverage of your heating system. Drain it.