Mercruiser 898 hot water heater?

[old islander]

Hi Boaters,
1978 898 I have steaming hot water coming out of the tell tale holes at the top of lower unit. Manifolds are hot to the touch, but not hot enough to burn my hand. The temp gauge is not much help. It starts out yellow, then has a large green portion followed by red if the needle is pegged. Running on muffs with a good supply of cool water. Ran about 10-15 minutes and the gauge just starts to touch the green portion on the gauge. I don't remember the out stream of water being that hot. Thermostat problem?
Also, port side is hotter then starboard.

 

[alldodge]

Hi Boaters,
1978 898 I have steaming hot water coming out of the tell tale holes at the top of lower unit. Manifolds are hot to the touch, but not hot enough to burn my hand. The temp gauge is not much help. It starts out yellow, then has a large green portion followed by red if the needle is pegged. Running on muffs with a good supply of cool water. Ran about 10-15 minutes and the gauge just starts to touch the green portion on the gauge. I don't remember the out stream of water being that hot. Thermostat problem?
Also, port side is hotter then starboard.

Don't see an issue, your running on muffs and they don't supply enough water to keep everything normal.

 

[old islander]

So I ran around to three different Mercruiser dealers yesterday. None had a new thermostat. One place said they did not have stat or gasket. After reading the gasket number to him...he had the gasket and he looked it up wrong. Note to self.., always have the correct part number before you go... I'm telling you, when you say "1978" to these young kids at the parts counter these days, your greeted by a wide eyed stare with a slight look of panic in their eyes. So my question is, Can I run a 160 degree thermostat instead of a 140? Will this cause damage to anything? If not I will order and wait for the 140.

 

[alldodge]

So I ran around to three different Mercruiser dealers yesterday. None had a new thermostat. One place said they did not have stat or gasket. After reading the gasket number to him...he had the gasket and he looked it up wrong. Note to self.., always have the correct part number before you go... I'm telling you, when you say "1978" to these young kids at the parts counter these days, your greeted by a wide eyed stare with a slight look of panic in their eyes. So my question is, Can I run a 160 degree thermostat instead of a 140? Will this cause damage to anything? If not I will order and wait for the 140.

IMO, his would not be an issue, actually the engine runs better when it is a bit hotter. That said, I don't know what temp waters your running in and if the water is warm it could have an impact. Merc uses the 140 to keep the corrosion down when in salt water using open cooling. If your in fresh water there should be no issue. As before this is your boat and this is just my opinion