1993 Mercruiser 350 Overheat

Have a 1993 Mercruiser 350 inboard. have replaced Thermostat housing , thermostat, water pump and water circulation pump. Still overheating any ideas

Is this a INBOARD or INBOARD/OUTBOARD?

Do you have a outdrive?
Or do you have a drive shaft to the prop?

is this a fresh water use or salt water use?

Is this a raw water cooled or a closed cooling system (heat exchanger in system)?


Either way, there are only so many issues that cause over heating

1. lack of water coming in..................usually bad impeller or pinched hose or clogged passage
2. Lack of water getting out................usually bad elbows, rusted and the scale has clogged/reduced the output of water flow
3. bad thermostat or wrong thermostat. Many replace with automotive of a higher rating..........most marine are either 140 or 160 degree set points.
4. bad sending unit


Maybe some additional information would be helpful