Water Tempature???

[BIGDODGEJOHN]

I Have A 1977 Silverline 17' Nantucket. I Just Got It Two Days Ago, I Took It Out Today For The First Time,but The Water Temp Was Jumping From 120-170. What Is The Ideal Water Tempature? Thanks. It Has A 305 Mercruiser

 

[Silvertip]

Re: Water Tempature???

When you start the engine it's obviously cold, just like your car so the temp gauge will read cold until it begins to warm up. The engine probably has a 160 thermostat which partially blocks the flow of cooling water through the engine to aid in quicker warm up. When engine temperature gets to 160 the thermostat opens and cool water flows in again. Once engine temp stabilizes it should run 160 or so. What you are observing is normal.