Join Date: Aug 2001
Location: Noank, Connecticut, USA
Thanked 63 Times in 62 Posts
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Re: Overheated my Yanmar 20gm20f
One of the things I checked before checking the freshwater side coolant level was the raw water impeller and it's fine.
The impeller on the freshwater side has not been checked yet but it seems that this is more along the lines of an automotive pump and running it dry for a short period would not effect the impeller.
I think I found the coolant leak. The lower "drain valve" with the clear plastic tube attached has a round nob for opening/closing. I noticed coolant coming out when I refilled with antifreeze. I tried tightening it and it seems that the nob will turn all the way past where it starts to feel like it's closing, leading me to believe the valve was over-tightened in the past and is now stripped or broken internally. I have yet to remove it as I could fiddle with the valve and get the antifreeze to stop leaking and only drip when running.
I'll probably have to order the part, so, my next question is, can I simply plug the hole with a properly sized bolt and run the engine until the part comes in?