I am referencing the Official Yanmar Service Manual for the 2gm20f.

One connection is a plug on the fresh water pump on the hose side that
leads from the heat exchanger. The other is a plug on the side of the
thermostat housing that leads to the heat exchanger. They are both
3/8" npt fittings.



On Mon, 29 Mar 2004 16:27:45 -0400, none
wrote:


I have an 18HP yanmar 2cyl and would like to put in an aux heater from the
internal cooling system (glycol). There are many plugs, thermhousing, side
of block etc... so i am unsure where to tie in for a send return that
won't affect the cooling of the motor. any thoughts?
rick