Home › Forum › Ask A Member › 1985 johnson 9.9 running temp › Re: 1985 johnson 9.9 running temp
Well, 190 is too hot, but I like that it cools down a bit when throttled up. This engine has a pressure controlled spring on the thermostat that allows it to be pushed off its seat with higher water pressure, which more or less bypasses the thermostat. You mention that your barrel water temp is 90 degrees which is pretty warm, so this might be the only issue. These engines like to get pretty warm when running slowly, which is a good thing, they run much hotter than older engines with no thermostat. Your temperature comes down a bit when throttle up which is a good indicator as well.
I would definitely take it for a run on a boat to re-evaluate. Post some pictures of the engine also so we can guess if it has been used in salt water. The engine sat for 20yrs, so hopefully the grommet is not an issue. You installed the complete kit, was it an OEM kit or aftermarket? Do you recall how the gearcase hsg looked under the SS impeller plate?