Test run
I did get the boat going and we went for a test ride yesterday.
Motor ran great but i still get a large gap between temp readings. If I let the boat idle, the temp will read 120. If I cruise the boat at 3500 rpm, the temp will slowly get to 200. Back off the throttle to 1200 and the temp will drop down to 120.
I did not overheat but I did get coolant releasing into the overflow container.
My question - If I have a 160 degree thermostat, why a 80 degree sway in temp?
Items I changed so far:
1) Upgraded from 3" to 4" heat exchanger. Checked and cleaned exchanger.
2) Replaced the raw water pump three times. The last time replaced the housing as well.
3) Replaced the riser.
4) Removed the water cooled voltage regulator and ran a new hose from the transom to the heat exchanger
5) Removed the head, machined and re-installed
6) New thermostat
What else is left?
My only thoughts now are something in the flow of coolant on the fresh water side. Either the thermostat or the engine circulating pump. I installed the thermostat with the springs down ( I have the old stye 470) perhaps I have the incorrect thermostat?
Any thoughts?
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