srm
Well-Known Member
Am feeling slightly puzzled.
Engine runs fine, no problems. It is a raw sea water cooled Yanmar 2GM20.
However, decided to check internal zinc anodes as I do not know when or even if previous owners had looked at them. Zinc in block was totally gone, so replaced.
Zinc in head was difficult to remove as it was coated with salt encrustations to a slightly larger diameter than the hole. Cleaned to bright metal and refitted.
It was only afterwards that I realised no water had come out of the block when removing the anode plug. Is this normal? Intuition suggests that the block should be full of sea water coolant. Engine had been run the day before and afterwards without any problems.
The engine is mounted above static waterline. Intake is in one hull below waterline (obviously). None return valve in pipe at waterline (which is fitted the correct way around), then up to strainer at deck level, about 1 metre above waterline.
Strainer has clear top and bright orange float inside so I can see at a glance if system is full or not. From strainer down hill pipe run to engine cooling water pump.
Its left me wondering if the engine block should be primed, and if so how as I do not remember anything to that effect in the owner's manual.
Any ideas?
Engine runs fine, no problems. It is a raw sea water cooled Yanmar 2GM20.
However, decided to check internal zinc anodes as I do not know when or even if previous owners had looked at them. Zinc in block was totally gone, so replaced.
Zinc in head was difficult to remove as it was coated with salt encrustations to a slightly larger diameter than the hole. Cleaned to bright metal and refitted.
It was only afterwards that I realised no water had come out of the block when removing the anode plug. Is this normal? Intuition suggests that the block should be full of sea water coolant. Engine had been run the day before and afterwards without any problems.
The engine is mounted above static waterline. Intake is in one hull below waterline (obviously). None return valve in pipe at waterline (which is fitted the correct way around), then up to strainer at deck level, about 1 metre above waterline.
Strainer has clear top and bright orange float inside so I can see at a glance if system is full or not. From strainer down hill pipe run to engine cooling water pump.
Its left me wondering if the engine block should be primed, and if so how as I do not remember anything to that effect in the owner's manual.
Any ideas?
