Engine cooling hose

[Richard Murphy]

After viewing a few pictures of small Yanmar engines installed in Ericson boats, I am not sure of the purpose of this hose assy. According to the Yanmar parts book, the stock hose is aprox. 10" long and runs from the thermostat to the mixing elbow. My boat has the yanmar hose installed and runs good. Thinking that this hose that was installed in the engine compartment but not hooked up had somthing to do with vacuum break, so I hooked it up in place of the stock hose. In addition to engine cooling exiting the transom, I am getting a discharge of cooling water from a small thru hull fitting in the transom which is plumbed to this cooling line. Anyone know whats up.??
Thanks
Rich

 

[Emerald]

From your description, looks like you have a simple siphon break. The small line should and will always have a small amount of water coming out of it in addition to the exhaust discharge. This is because water is always flowing through the siphon break, and some will go down the small line, but most will go to the mixing elbow. Make sure that this fitting with the small line and the two primaries is located above the water line. If it's not above the water line, the siphon break portion won't work properly.

 

[Richard Murphy]

Thank you David for the reply. What would be the consequence of continuing to run without this antisiphon hose? One benifit of not running the hot engine cooling water thru this 6' hose is, the engine compartment would not heat up anymore the necessary.

Rich