2002 johnson temp gauge problem

[Walleye2487!]

Hi my parents have a pontoon with a johnson 2002 40hp and temp gauge keeps coming on . The motor is spitting water good what could it be ?

[TomP.]

Just because it is spitting water does not mean it is getting enough water. When was the last time the water pump was replaced.

[Ozark Bob]

Thermostat could be an issue as well. Bob

[REW]

Walleye,
Before doing anything else, drop the lower unit and replace the water pump housing and impeller and give it a go.

The impeller change will very likely fix the issue.

However, if you want to be thorough, change the thermostat also at the same time.

Note:
When, changing the impeller, take a garden hose and blasting at the location where the impeller was located, blast out the lower unit housing from the water pump back to the water inlet, in case there might be weeds or some other issue in the water passages in the lower unit.

Good luck .